Change search
Refine search result
123 1 - 50 of 108
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Afzal, Md
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Arteaga, I. Lopez
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Kharyton, V.
    INVESTIGATION OF DAMPING POTENTIAL OF STRIP DAMPER ON A REAL TURBINE BLADE2016In: PROCEEDINGS OF THE ASME TURBO EXPO: TURBINE TECHNICAL CONFERENCE AND EXPOSITION, 2016, VOL 7A, AMER SOC MECHANICAL ENGINEERS , 2016Conference paper (Refereed)
    Abstract [en]

    This paper investigates the damping potential of strip dampers on a real turbine bladed disk. A 3D numerical friction contact model is used to compute the contact forces by means of the Alternate Frequency Time domain method. The Jacobian matrix required during the iterative solution is computed in parallel with the contact forces, by a quasi-analytical method. A finite element model of the strip dampers, that allows for an accurate description of their dynamic properties, is included in the steady-state forced response analysis of the bladed disk. Cyclic symmetry boundary conditions and the multiharmonic balance method are applied in the formulation of the equations of motion in the frequency domain. The nonlinear forced response analysis is performed with two different types of boundary conditions on the strip: (a) free-five and (b) elastic, and their influence is analyzed. The effect of the strip mass, thickness and the excitation levels on the forced response curve is investigated in detail.

  • 2.
    Afzal, Mohammad
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Arteaga, Ines Lopez
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Eindhoven University of Technology, Netherlands.
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Numerical analysis of multiple friction contacts in bladed disks2018In: International Journal of Mechanical Sciences, ISSN 0020-7403, E-ISSN 1879-2162, Vol. 137, p. 224-237Article in journal (Refereed)
    Abstract [en]

    The damping potential of multiple friction contacts in a bladed disk is investigated. Friction contacts at tip shrouds and strip dampers are considered. It is shown that friction damping effectiveness can be potentially increased by using multiple friction contact interfaces. Friction damping depends on many parameters such as rotational speed, engine excitation order and mode family and therefore it is not possible to damp all the critical resonances using a single kind of friction contact interface. For example, a strip damper is more effective for the low nodal diameters, where blade/disk coupling is strong. The equations of motion of the bladed disk with multiple friction contacts are derived in the frequency domain for a cyclic structure with rotating excitations. A highly accurate method is used to generate the frequency response function (FRF) matrix. Furthermore, a finite element contact analysis is performed to compute the normal contact load and the contact area of the shroud interface at operating rotational speed. The multiharmonic balance method is employed in combination with the alternate frequency time domain method to find the steady state periodic solution. A low-pressure turbine bladed disk is considered and the effect of the engine excitation level, strip mass, thickness and the accuracy of FRF matrix on the nonlinear response curve are investigated in detail.

  • 3.
    Afzal, Mohammad
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics. kth.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics. Eindhoven University of Technology, the Netherlands.
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    A formulation of the Jacobian matrixfor 3D numerical friction contact model applied to turbine blade shroud contactIn: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568Article in journal (Other academic)
    Abstract [en]

    An analytical expression is formulated to compute the Jacobian matrix for 3D friction contact modelling that eciently evaluates the matrix while computing the friction contact forces in the time domain by means of the alternate frequency time domain approach. The developed expression is successfully used for thecalculation of the friction damping on a turbine blade with shroud contact interface having an arbitrary 3Drelative displacement. The analytical expression drastically reduces the computation time of the Jacobian matrix with respect to the classical finite dierence method, with many points at the contact interface. Therefore,it also significantly reduces the overall computation time for the solution of the equations of motion,since the formulation of the Jacobian matrix is the most time consuming step in solving the large set of nonlinear algebraic equations when a finite dierence approach is employed. The equations of motion are formulated in the frequency domain using the multiharmonic balance method to accurately capture the nonlinear contact forces and displacements. Moreover, the equations of motion of the full turbine blade model are reduced to a single sector model by exploiting the concept of cyclic symmetry boundary condition for aperiodic structure. Implementation of the developed scheme in solving the equations of motion is proved to be effective and significant reduction in time is achieved without loss of accuracy.

  • 4.
    Afzal, Mohammad
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    An analytical calculation of the Jacobian matrix for 3D friction contact model applied to turbine blade shroud contact2016In: Computers & structures, ISSN 0045-7949, E-ISSN 1879-2243, Vol. 177, p. 204-217Article in journal (Refereed)
    Abstract [en]

    An analytical expression is formulated to compute the Jacobian matrix for 3D friction contact modeling that efficiently evaluates the matrix while computing the friction contact forces in the time domain by means of the alternate frequency time domain approach. The developed expression is successfully used for the calculation of the friction damping on a turbine blade with shroud contact interface having an arbitrary 3D relative displacement. The analytical expression drastically reduces the computation time of the Jacobian matrix with respect to the classical finite difference method, with many points at the contact interface. Therefore, it also significantly reduces the overall computation time for the solution of the equations of motion, since the formulation of the Jacobian matrix is the most time consuming step in solving the large set of nonlinear algebraic equations when a finite difference approach is employed. The equations of motion are formulated in the frequency domain using the multiharmonic balance method to accurately capture the nonlinear contact forces and displacements. Moreover, the equations of motion of the full turbine blade model are reduced to a single sector model by exploiting the concept of cyclic symmetry boundary condition for a periodic structure. Implementation of the developed scheme in solving the equations of motion is proved to be effective and significant reduction in time is achieved without loss of accuracy.

  • 5.
    Afzal, Mohammad
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez-Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Adaptive control of normal load at the friction interface of bladed disks using giant magnetostrictive materialIn: Journal of Vibration and Control, ISSN 1077-5463, E-ISSN 1741-2986Article in journal (Other academic)
    Abstract [en]

    A novel application of magnetostrictive actuators in underplatform dampers of bladed disks is proposed for adaptive control of the normal load at the friction interface in order to achieve the desired friction damping in the structure. Friction damping in a bladed disk depends on many parameters such as rotational speed, engine excitation order, nodal diameter, contact stiffness, friction coefficient and normal contact load. However, all these parameters have a fixed value at an operating point. On the other hand, the ability to vary some of these parameters such as the normal contact load is desirable in order to obtain an optimum damping in the bladed disk at different operating conditions. Under the influence of an external magnetic field, magnetostrictive materials develop an internal strain that can be exploited to vary the normal contact load at the friction interface, which makes them a potentially good candidate for this application. A commercially available magnetostrictive alloy, Terfenol-D is considered in this analysis that is capable of providing magnetostrain up to 0.002 under prestress and a blocked force over 1500 N. A linearized model of the magnetostrictive material, which is accurate enough for a DC application, is employed to compute the output displacement and the blocked force of the actuator. A nonlinear finite element contact analysis is performed to compute the normal contact load between the blade platform and the underplatform damper as a result of magnetostrictive actuation. The contact analysis is performed for different mounting configurations of the actuator and the obtained results are discussed. The proposed solution is potentially applicable to adaptively control vibratory stresses in bladed disks and consequently to reduce failure due to high-cycle fatigue. Finally, the practical challenges in employing magnetostrictive actuators in underplatform dampers are discussed.

  • 6.
    Afzal, Mohammad
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez-Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Eindhoven University of Technology.
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Numerical analysis of multiple friction contacts in bladed disksIn: International Journal of Mechanical Sciences, ISSN 0020-7403, E-ISSN 1879-2162Article in journal (Other academic)
    Abstract [en]

    The damping potential of multiple friction contacts in a bladed disk, tip shroud and strip damper is investigated, showing that friction damping effectiveness can be potentially increased by using multiple friction contact interfaces. Friction damping depends on many parameters such as rotational speed, engine excitation order and mode family and therefore it is not possible to damp all the critical resonances using a single friction contact interface. For example, a strip damper is more effective for the low nodal diameters, where blade/disk coupling is strong. The equations of motion of the bladed disk with multiple friction contacts are derived in the frequency domain for a cyclic structure with rotating excitations and a highly accurate method is used to generate the frequency response function (FRF) matrix. Furthermore, a finite element contact analysis is performed to compute the normal contact load and the contact area of the shroud interface at operating rotational speed. The multiharmonic balance method is employed in combination with the alternate frequency time domain method to find the approximate steady state periodic solution. A low-pressure turbine bladed disk is considered and the effect of the engine excitation level, strip mass, thickness and the accuracy of FRF matrix on the nonlinear response curve are investigated in detail.

  • 7.
    Amlinger, Hanna
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Botling, Fredrik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Leth, Siv
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Operational deflection shapes of a PWM-fed traction motor2016In: Conference Proceedings of the Society for Experimental Mechanics Series, Springer, 2016, p. 209-217Conference paper (Refereed)
    Abstract [en]

    Operational deflection shapes of an asynchronous traction motor for railway applications are investigated. The radiated noise from the tractionmotor on a train is, especially at low speeds, dominated by noise generated by electromagnetic forces. The tested motor is fed by a pulse-width-modulated (PWM) frequency converter for which the voltage is modulated as a series of pulses that are switched with a certain frequency. In this case, PWM force lines can be expected to influence the radiated noise. Therefore, detailed knowledge about the frequencies and deflection shapes of vibrations generated by PWM forces is of great importance for understanding and controlling the radiated noise and its spectral content. Vibration levels are measured on the stator shield and the operational deflection shapes are studied for several PWM switching frequencies and motor speeds. The deflection shapes with the largest vibration levels are determined. These are then compared to the expected excitation resulting from the pure PWM force lines. Changing the switching frequency, will shift the frequencies of the exciting forces. An appropriate selection of the PWM switching frequency is therefore important for the resulting acoustic radiation from the motor. © The Society for Experimental Mechanics, Inc. 2016.

  • 8.
    Amlinger, Hanna
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Leth, Siv
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Impact of PWM switching frequency on the radiated acoustic noise from a traction motor2017In: 2017 20th International Conference on Electrical Machines and Systems, ICEMS 2017, Institute of Electrical and Electronics Engineers Inc. , 2017Conference paper (Refereed)
    Abstract [en]

    The radiated acoustic noise from a traction motor at low speeds is dominated by the noise of electromagnetic origin. For a motor operated from pulse width modulated (PWM) converters, the switching frequency of the converter will have a large impact on the noise. The total harmonic distortion of the motor phase currents and thus also the exciting forces, will decrease with increasing switching frequency. Furthermore, changing the switching frequency will shift the frequencies of the exciting forces, hence have an influence on the coincidence with structural resonances of the motor. Tests have been performed on a traction motor and a decrease in sound pressure level with increasing switching frequency has been quantified and analyzed.

  • 9.
    Amlinger, Hanna
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Leth, Siv
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Reduction of radiated acoustic noise of a traction motor at PWM converter operationManuscript (preprint) (Other academic)
  • 10. Boere, Stijn
    et al.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Kuijpers, Ard
    Nijmeijer, Henk
    Tyre/road interaction model for the prediction of road texture influence on rolling resistance2014In: International Journal of Vehicle Design, ISSN 0143-3369, E-ISSN 1741-5314, Vol. 65, no 2-3, p. 202-221Article in journal (Refereed)
    Abstract [en]

    A novel modelling approach to predict the influence of road texture on the rolling resistance of car tyres is presented where the large static tyre deformations and the small texture induced tyre vibrations are treated separately. The energy dissipation due to the large continuous cyclic deformation of the tyre cross section for a treadless tyre subject to nominal load on a smooth road is determined in a non-linear steady-state rolling analysis on an FEM tyre model. The additional energy dissipation resulting from the con tact forces and tyre vibrations due to the combined effect of the tread profile and the road texture, are determined based on a modal representation of the deformed tyre. The predicted rolling resistance coefficients are compared to experimental data. Although an offset in the absolute rolling resistance levels can be observed, the model predicts the correct trend regarding the increase of rolling resistance with increasing texture depth.

  • 11.
    Boere, S.W.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Kuijpers, A.H.W.M.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Prediction of road texture influence on rolling resistance and tire/road noise2009In: Proceedings of Euronoise 2009, 2009Conference paper (Other academic)
  • 12.
    Botling, Fredrik
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Amlinger, Hanna
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Leth, Siv
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Vibro-acoustic modal model of a traction motor for railway applications2016In: Conference Proceedings of the Society for Experimental Mechanics Series, Springer, 2016, p. 197-208Conference paper (Refereed)
    Abstract [en]

    A vibro-acoustic modal model of a traction motor for railway applications is presented based on an experimental modal analysis of the system. Noise requirements for railway traction motors are getting more and more demanding as part of the overall levels of new rolling stock. It is therefore of great interest to understand and predict the vibro-acoustic behaviour of electromagnetic noise generated by traction motors. The modal parameters are derived from an experimental modal analysis. The primary source for the radiated sound of the tested traction motor is the radial deflections of the stator shield. The modal parameters for the radial deflections are implemented in a reduced order modal model in a state space format using Matlab/Simulink. Only the structural modes that have a match in both the frequency and the spatial domain with the excited electromagnetic force will cause important vibro-acoustic response. This makes it possible to create an accurate and efficient reduced order modal model with only a fraction of the total number of structural modes. The simulation results from the modal model are compared to measurements of operational deflection shapes and acoustic measurements of the motor. © The Society for Experimental Mechanics, Inc. 2016.

  • 13.
    Botling, Fredrik
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Leth, Siv
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Combined Experimental and Analytical Vibro-Acoustic Model of an Electrical Motor2016In: Journal of Experimental MechanicsArticle in journal (Other academic)
    Abstract [en]

    A vibro-acoustic modal model of a traction motor forrailway applications is presented based on an experimentalmodal analysis of the system. Noise requirements forrailway traction motors are getting more and moredemanding as part of the overall levels of new rolling stock.It is therefore of great interest to understand and predict thevibro-acoustic behaviour of electromagnetic noisegenerated by traction motors. The modal parameters arederived from an experimental modal analysis. The primarysource for the radiated sound of the tested traction motor isthe radial deflections of the stator shield. The modalparameters for the radial deflections are implemented in areduced order modal model in a state space format usingMatlab/Simulink. Only the structural modes that have amatch in both the frequency and the spatial domain withthe electromagnetic excitation force will cause animportant vibro-acoustic response. This makes it possibleto create an accurate and efficient reduced order modalmodel with only a fraction of the total number of structuralmodes. The simulation results from the modal model arecompared to measured levels of vibration and acousticmeasurements of the motor.

  • 14.
    Botling, Fredrik
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Leth, Siv
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Modelling framework for electromagnetic noise generation from traction motors2016Conference paper (Refereed)
  • 15.
    Botling, Fredrik
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Leth, Siv
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Modelling framework for electromagnetic noise generation from traction motors2016In: Journal of Notes on Numerical Fluid Mechanics and Multidisciplinary DesignArticle in journal (Other academic)
    Abstract [en]

    Electromagnetic noise from traction motors is often the single most dominating noise source from trains at low trainspeeds. This electromagnetic noise is tonal and annoying for both passengers on the train and people near the track andon the platform. A thorough understanding of the cause and the prediction of the electromagnetic noise is needed to beable to design low noise components. This paper describes a real time multi-physics modelling framework forprediction of the audible electromagnetic noise generated by traction motors fed by power converters. The cause of theelectromagnetic noise is influenced by several different domains. To be able to fully simulate the final acoustic sound,all these domains needs to be modelled and simulated together. Simulations of some relevant operational conditionsfor acoustic noise generation has been performed and discussed. Some of these results have been compared to realmeasurements from a converter fed traction motor.

  • 16. Chen, L. S.
    et al.
    Polifke, W.
    Hosseini, N.
    Teerling, O. J.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. Eindhoven University of Technology, Netherlands.
    Kornilov, V.
    De Goey, P.
    Acoustic scattering behavior of a 2D flame with heat exchanger in cross-flow2016In: ICSV 2016 - 23rd International Congress on Sound and Vibration: From Ancient to Modern Acoustics, International Institute of Acoustics and Vibrations , 2016Conference paper (Refereed)
    Abstract [en]

    In practical heat production systems, premixed flames with cold heat exchanger in cross-flow is a widely used configuration. Self-excited thermoacoustic instabilities often occur in such systems. A practical way to predict the presence of the instabilities is the network model approach. In the present study, the configuration flame - heat exchanger is analyzed numerically. We first analyze the system as a network of segregated elements. Based on the resulting acoustic scattering matrix, the role of the heat exchanger as an amplifier of the flame resonant frequencies will be discussed. Then, results from the 1D network modeling are compared to results of compressible numerical simulations, performed for several distances between flame and heat exchanger. Finally, the limits to the validity of the segregated network model approach are discussed.

  • 17. Chen, Lin Strobin
    et al.
    Polifke, Wolfgang
    Hosseini, Naseh
    Teerling, Omke Jan
    Arteaga, Ines Lopez
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Kornilov, Viktor
    de Goey, Philip
    ACOUSTIC SCATTERING BEHAVIOR OF A 2D FLAME WITH HEAT EXCHANGER IN CROSS-FLOW2016In: PROCEEDINGS OF THE 23RD INTERNATIONAL CONGRESS ON SOUND AND VIBRATION: FROM ANCIENT TO MODERN ACOUSTICS, 2016Conference paper (Refereed)
    Abstract [en]

    In practical heat production systems, premixed flames with cold heat exchanger in cross-flow is a widely used configuration. Self-excited thermoacoustic instabilities often occur in such systems. A practical way to predict the presence of the instabilities is the network model approach. In the present study, the configuration flame - heat exchanger is analyzed numerically. We first analyze the system as a network of segregated elements. Based on the resulting acoustic scattering matrix, the role of the heat exchanger as an amplifier of the flame resonant frequencies will be discussed. Then, results from the 1D network modeling are compared to results of compressible numerical simulations, performed for several distances between flame and heat exchanger. Finally, the limits to the validity of the segregated network model approach are discussed.

  • 18.
    Hoeijmakers, M.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Kornilov, V.N.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    de Goey, L.P.H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Effect of burner partitioning on system thermo-acoustics2011In: ICSV18, 2011Conference paper (Other academic)
  • 19. Hoeijmakers, Maarten
    et al.
    Kornilov, Viktor
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Arteaga, Ines Lopez
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    de Goey, Philip
    Nijmeijer, Henk
    Flame dominated thermoacoustic instabilities in a system with high acoustic losses2016In: Combustion and Flame, ISSN 0010-2180, E-ISSN 1556-2921, Vol. 169, p. 209-215Article in journal (Refereed)
    Abstract [en]

    The thermoacoustic stability behaviour of a flame is experimentally investigated in the presence of large acoustic losses. Recently it has become clear that under such conditions an instability can occur due to an intrinsic local feedbackloop at the heat source. The experimental results confirm that despite significant acoustic losses, thermoacoustic instabilities can still be present. These findings imply that the effectiveness of passive thermoacoustic damping devices is limited by the intrinsic stability properties of the flame. (C) 2016 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  • 20. Hoeijmakers, Maarten
    et al.
    Kornilov, Viktor
    Arteaga, Ines Lopez
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Eindhoven University of Technology, Netherlands .
    de Goey, Philip
    Nijmeijer, Henk
    Flames in context of thermo-acoustic stability bounds2015In: Proceedings of the Combustion Institute, ISSN 1540-7489, Vol. 35, p. 1073-1078Article in journal (Refereed)
    Abstract [en]

    Bounds are derived for the acoustic losses such that a thermoacoustic system with a given flame can be guaranteed to be stable. The analysis is based on the flame's acoustic input-to-output properties represented by its scattering matrix. The developed analytical and numerical techniques allow estimating the maximum reflection coefficients (equivalently - acoustic losses) which are sufficient to ensure stable operation of a given burner. It is shown that the calculated numerical upper-bound is less conservative than the analytical one. The frequency dependence of the required acoustic losses provides (i) a thermo-acoustic signature of the flame and (ii) guidelines for the proper design of the up-and downstream acoustics from the flame. The method is illustrated on two burners/flames of premixed multiple Bunsen type. The frequency dependence of the upper bounds allows to identify those frequency ranges where the flame is more likely to cause instability of the complete system.

  • 21. Hoeijmakers, Maarten
    et al.
    Kornilov, Viktor
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Eindhoven University of Technology, Netherlands.
    de Goey, Philip
    Nijmeijer, Henk
    Intrinsic instability of flame-acoustic coupling2014In: Combustion and Flame, ISSN 0010-2180, E-ISSN 1556-2921, Vol. 161, no 11, p. 2860-2867Article in journal (Refereed)
    Abstract [en]

    This paper shows that a flame can be an intrinsically unstable acoustic element. The finding is clarified in the framework of an acoustic network model, where the flame is described by an acoustic scattering matrix. The instability of the flame acoustic coupling is shown to become dominating in the limit of no acoustic reflections. This is in contrast to classical standing-wave thermoacoustic modes, which originate from the positive feedback loop between system acoustics and the flame. These findings imply that the effectiveness of passive thermoacoustic damping devices is limited by the intrinsic stability properties of the flame.

  • 22. Hoeijmakers, Maarten
    et al.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Kornilov, Viktor
    Nijmeijer, Henk
    de Goey, Philip
    Accuracy assessment of thermoacoustic instability models using binary classification2013In: International Journal of Spray and Combustion Dynamics, ISSN 1756-8277, Vol. 5, no 3, p. 201-223Article in journal (Refereed)
    Abstract [en]

    We apply binary classification theory to assess the (in)stability prediction accuracy of thermoacoustic models. It is shown that by applying such methods to compare a large set of stability predictions and experiments it is possible to gain valuable qualitative insight in different aspects of prediction quality. The approach is illustrated with a 2-port model and a large experimental data set. The presented framework provides an unified and practical tool to answer questions such as (i) What is the chance that a stable prediction will be correct? and (ii) How conservative is the model? It is shown that the most suitable quality indicator is strongly dependent on the actual purpose of the model. The method provides a solid starting point for model comparison and optimization.

  • 23. Hosseini, N.
    et al.
    Kornilov, V. N.
    Teerling, O. J.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. Eindhoven Univ Technol, Dept Mech Engn, POB 513, NL-5600 MB Eindhoven, Netherlands.
    de Goey, P.
    Evaluating thermoacoustic properties of heating appliances considering the burner and heat exchanger as acoustically active elements2018In: Combustion and Flame, ISSN 0010-2180, E-ISSN 1556-2921, Vol. 191, p. 486-495Article in journal (Refereed)
    Abstract [en]

    Heat exchangers are an essential constituent part of many combustion systems. The thermoacoustic instability in such systems is a common problem and it has been studied extensively. However, the heat exchanger has not gained much attention in the field of combustion thermoacoustics, leading to a lack of knowledge about the thermoacoustic interactions between the burner and the heat exchanger. In this paper, a modeling approach is introduced to study these interactions in an academic representation of a heating appliance, comprised of a perforated slit burner and a tube heat exchanger. Both elements are considered thermally and acoustically active. A CFD model is used in a two-dimensional domain to simulate the response of the system to small amplitude broadband velocity perturbations. The thermochemical and acoustic coupling between the burner and the heat exchanger is investigated and a method is introduced to decouple their effects and study them separately. The extents to which this method is valid are addressed by varying the distance between the elements. Results show that as long as the flames do not impinge on the heat exchanger surface, a linear network modeling approach can be applied to construct the acoustic response of the composed configuration from the responses of its constituting elements. This approach requires registering the average velocity on a properly chosen intermediate plane between the burner and heat exchanger. Choosing this plane may be to some point difficult, i.e. when the burner and heat exchanger are close and cannot be considered independent. Moreover, when flame impingement occurs, the interactions between the flame and heat exchanger affect their individual thermoacoustic behaviors and the burner plus heat exchanger assembly needs to be considered as one coupled acoustic element. Particularly, flame impingement changes the phase of the heat absorption response of the heat exchanger and it may significantly alter the acoustic properties of the coupled assembly. The physics lying behind the effects of such interactions on the thermoacoustics of the system is discussed. The obtained results signify that a correct stability prediction of an appliance with burner and heat exchangers requires considering active thermoacoustic behavior of both elements as well as their interactions.

  • 24. Hosseini, N.
    et al.
    Kornilov, V.
    Teerling, O. J.
    Arteaga, Ines Lopez
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    De Goey, L. P. H.
    Transfer function calculations of segregated elements in a simplified slit burner with heat exchanger2015In: 22nd International Congress on Sound and Vibration, ICSV 2015, International Institute of Acoustics and Vibrations , 2015Conference paper (Refereed)
    Abstract [en]

    A simplified burner-heat exchanger system is numerically modelled in order to investigate the effects of different elements on the response of the whole system to velocity excitation. We model the system in a 2D CFD code, considering a linear array of multiple Bunsen-type flames with heat exchanger tubes downstream the flames. Thermoacoustic instability is one of the main issues in lean premixed combustion systems, especially domestic boilers. In compact condensing boilers the close distance between the burner surface and the heat exchanger has increased the importance of studying the interactions between the flames and the heat exchanger. The elements corresponding to the heat balance in the system are the flame as heat source and burner deck and heat exchanger as heat sinks. We use both transfer function and transfer matrix approaches to identify the response of these elements to a step function excitation of velocity at the inlet of the domain. Steady-state simulations show that the contribution of the burner deck to the heat balance of the whole system is negligible, leaving the flame and heat exchanger as main contributors to the response of the system. We separately investigate the behavior of these two elements by modeling cases with flame only and heat exchanger only. Then we calculate the behavior of the combined system and compare it to the results of modeling a case with flame and heat exchanger together. These results show that, assuming linear behavior of the elements, it is possible to predict the system behavior via its constructing elements. Further investigations of the effects of other parameters and the limits, within which the assumptions are valid, are currently in progress.

  • 25. Hosseini, N.
    et al.
    Kornilov, V.
    Teerling, O. J.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Mechanical Engineering Department, Eindhoven University of Technology, Eindhoven, Netherlands .
    De Goey, P.
    Development of a numerical model for obtaining flame transfer function in a simplified slit burner with heat exchanger2014In: 21st International Congress on Sound and Vibration 2014, ICSV 2014, 2014, Vol. 2, p. 1581-1588Conference paper (Refereed)
    Abstract [en]

    The goal of the present work is to develop a model to investigate the interactions between a burner and a heat exchanger, looking from a hydrodynamic and thermo-acoustic point of view. Thermo-acoustics of laminar premixed flames in open air have been studied by several researchers in the past decades. However, a burner in open air may behave differently compared to if situated in a combustion chamber enclosure. This could be related to the effect of temperature, the effect of flame shape (e.g. flames impinging on the heat exchanger walls in compact boilers), distribution of the flame on the burner deck, etc. The behavior of a linear array of a multiple Bunsen-type flames is studied on a 2D geometry in a CFD code to simulate the effects of heat exchanger addition on the thermo-acoustics of the flames. The location of the heat exchanger surface is varied for different conditions of power. A step profile velocity perturbation is used for obtaining the response of the flame represented within the flame transfer function approach. The calculated gain and phase of the flame transfer function are compared for different cases as the indicator of the thermo-acoustic behavior. Results show that the main parameter having considerable influence is the burner load and flame shape. The setup to experimentally investigate these effects will be constructed in near future.

  • 26.
    Jerrelind, Jenny
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Effects of non-linear wheel suspension bushing on vehicle response2012In: Proceedings of the ASME Design Engineering Technical Conferences And Computers And Information In Engineering Conference, Vol 6, ASME Press, 2012, p. 615-622Conference paper (Refereed)
    Abstract [en]

    This work presents an analysis of the effects of non-linear characteristics of a top mount bushing in the wheel suspension of a vehicle when evaluating vehicle characteristics such as comfort and handling. The investigation is performed by comparing simulation results from a quarter car model when using a non-linear bushing model and an approximated linear bushing model. It is revealed when analysing the results that there are differences in the response when comparing measures such as sprung mass acceleration, rattle space ratio and tyre-ground contact force. The conclusion is that the more detailed bushing model mainly affects the acceleration levels especially at high frequencies where the linear model underestimates the acceleration. The rattle space ratio and tyre-ground contact force are also affected but not to the same extent.

  • 27.
    Liu, Hao
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Finnveden, Svante
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Barbagallo, Mathias
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Wave propagation in sandwich panels with a poroelastic core2014In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 135, no 5, p. 2683-2693Article in journal (Refereed)
    Abstract [en]

    Wave propagation in sandwich panels with a poroelastic core, which is modeled by Biot's theory, is investigated using the waveguide finite element method. A waveguide poroelastic element is developed based on a displacement-pressure weak form. The dispersion curves of the sandwich panel are first identified as propagating or evanescent waves by varying the damping in the panel, and wave characteristics are analyzed by examining their motions. The energy distributions are calculated to identify the dominant motions. Simplified analytical models are also devised to show the main physics of the corresponding waves. This wave propagation analysis provides insight into the vibro-acoustic behavior of sandwich panels lined with elastic porous materials.

  • 28.
    Liu, Hao
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Finnveden, Svante
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Prediction of sound transmission through elastic porous material lined multilayer panels using a semi-analytical finite element methodManuscript (preprint) (Other academic)
  • 29.
    Liu, Hao
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    O'Reilly, Ciarán
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Finnveden, Svante
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Prediction of sound field in geometrically complex enclosures with the wave expansion methodManuscript (preprint) (Other academic)
  • 30.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics. Eindhoven University of Technology, The Netherlands.
    Green's functions for a loaded rolling tyre2011In: International Journal of Solids and Structures, ISSN 0020-7683, E-ISSN 1879-2146, Vol. 48, no 25-26, p. 3462-3470Article in journal (Refereed)
    Abstract [en]

    A new formulation to determine the unit impulse response (Green's) functions of a loaded rotating tyre in the vehicle-fixed (Eulerian) reference frame for tyre/road noise predictions is presented. The proposed formulation makes use of the set of eigenfrequencies and eigenmodes for the statically loaded tyre obtained from a finite element (FE) model of the tyre. A closed-form expression for the Green's functions of a rotating tyre in the Eulerian reference system as a function of the eigenfrequencies and eigenmodes of the statically loaded tyre is found. Non-linear effects during loading are accounted for in the FE model, while the frequency shift due to the rotational velocity is included in the calculation of the Green's functions. In the literature on tyre/road noise these functions are generally used to determine the tyre response during tyre/road contact calculations. The presented formulation opens the possibility to solve the contact problem directly in the Eulerian reference frame and to include local tyre softening due to non-linear effects while keeping the computational advantage of describing the tyre dynamics as a set of impulse response functions. The advantage of obtaining the Green's functions in the Eulerian reference system is that only the Green's functions corresponding to the potential contact zone need to be determined, which significantly reduces the computational cost of solving the tyre/road contact and since the mesh is fixed in space, a finer mesh can be used for the potential contact zone, improving the accuracy of the contact force calculations. Although these effects might be less pronounced if a more accurate tyre model is used, it is found that using the Green's functions of the loaded tyre in a contact force calculation leads to smaller forces than in the unloaded case, lower frequencies are present in the response and they decrease faster as the rotational velocity increases.

  • 31.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Influence of material damping on the prediction of road texture and tread pattern related rolling resistance2010In: Proceedings of the International Conference on Noise and Vibration Engineering, ISMA 2010 / [ed] P. Sas, B. Bergen, 2010, p. 881-892Conference paper (Other academic)
  • 32.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Eindhoven University of Technology, Department of Mechanical Engineering, Eindhoven, Netherlands .
    Tyre/road noise and vibration: Understanding their interaction and contribution to vehicle noise and fuel consumption2014In: 21st International Congress on Sound and Vibration 2014, ICSV 2014, 2014, Vol. 1, p. 51-63Conference paper (Refereed)
    Abstract [en]

    Tyre/road noise and vibration are the main sources of road traffic noise, which is an increasingly big problem in densely populated areas. At the same time, rolling resistance, caused by the energy losses in the tyre, is a significant part of the total vehicle losses and, therefore, directly affects fuel consumption and C02 emissions. In order to reduce both noise emissions and energy consumption a good understanding of tyre/road interaction and of the influence of tyre and road properties is needed. In this paper the main tyre and road parameters that influence tyre/road noise and rolling resistance are discussed. Special emphasis is placed on tyre/road contact, since the contact forces between tyre and road are the key to a reliable prediction of tyre/road noise, rolling resistance and wear. Although tyre/road models are widely applied to the prediction of tyre/road noise and low-noise road design, the potential of these models for low-rolling resistance road design is not yet fully exploited.

  • 33.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Eindhoven University of Technology, Netherlands.
    Vibro-acoustic sources in ground transportation2017In: Proceedings of ACOUSTICS 2017 Perth: Sound, Science and Society - 2017 Annual Conference of the Australian Acoustical Society, AAS 2017, Australian Acoustical Society , 2017Conference paper (Refereed)
    Abstract [en]

    Long term exposure to ground transportation (road and rail traffic) noise is, after air pollution, the main environmentrelated health stressor in densely populated areas and compromises the quality of life and, indirectly, the life expectations of millions of people. At speeds up to 130 km/h in road traffic and up to 300 km/h in rail traffic the main source of noise is the tyre/road (respectively wheel/rail) interaction. In this paper the sound and vibration generation mechanisms due to tyre/road and wheel/rail interaction are discussed, focusing on the similarities and differences between the sound and vibration generation mechanisms in these two systems. This perspective is further extended to the discussion of contact force modelling and characterization methods in both road and rail traffic systems.

  • 34.
    Lopez Arteaga, Ines
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Blok, C.A.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Energy dissipation of a friction damper: experimental validation2008In: PROCEEDINGS OF ISMA 2008 / [ed] P. Sas, B. Bergen, Leuven, KATHOLIEKE UNIV LEUVEN , 2008, p. 881-892Conference paper (Other academic)
    Abstract [en]

    Friction is frequently seen as an unwanted phenomenon whose influence has to be either minimised or controlled. In this work one of the positive sides of friction is investigated: friction damping. The friction inherently present in a system can be positively used to increase the total damping or alternatively, a friction damper can be designed. Friction dampers can be a cheap and efficient way to reduce the vibration levels of a wide range of mechanical systems. In the present paper the conclusions of previous analytic and numerical results regarding friction damping are validated with results of laboratory experiments, where the energy dissipated through friction is measured. The test set-up consists of a mass sliding on parallel ball-bearings, where additional friction is created by a sledge attached to the mass, which is pre-stressed against a friction plate. No care has been taken to ensure pure dry (Coulomb) friction. Nevertheless, the measured energy dissipation is in good agreement with the theoretical results for Coulomb friction.

  • 35.
    Lopez Arteaga, Ines
    et al.
    Eindhoven University of Technology.
    Blom, R. E. A.
    Roozen, N. B.
    Nijmeijer, H.
    Modelling vibrations on deformed rolling tyres - a modal approach2007In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 307, no 3-5, p. 481-494Article in journal (Refereed)
    Abstract [en]

    This paper examines an approach to model the vibrations of a deformed rolling tyre at low frequencies (below 500 Hz). The starting point for this approach is a finite element (FE) model of the tyre and the aim is to calculate the dynamic response of a rolling tyre including the details of its complex build up. This allows to relate the tyre design parameters to its vibro-acoustic properties. In this context, a modal approximation based on the eigenvalues and eigenvectors extracted from the detailed FE model of the tyre seems a computationally efficient possibility. In the proposed approach the natural frequencies and modeshapes of a deformed tyre are calculated in a standard FE package using the full (nonlinear) FE model. Subsequently, this modal base is transformed to determine the response of the rotating tyre in a fixed (Eulerian) reference frame. Furthermore, this approach makes it possible to define a receptance matrix for the rotating tyre. Results from relatively simple tyre models show that the effects of rotation are modelled correctly and are in accordance with results from literature.

  • 36.
    Lopez Arteaga, Ines
    et al.
    Eindhoven University of Technology.
    Busturia, J. M.
    Nijmeijer, H.
    Energy dissipation of a friction damper2004In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 278, no 3, p. 539-561Article in journal (Refereed)
    Abstract [en]

    In this paper the energy dissipated through friction is analysed for a type of friction dampers used to reduce squeal noise from railway wheels. A one degree-of-freedom system is analytically studied. First the existence and stability of a periodic solution are demonstrated and then the energy dissipated per cycle is determined as a function of the system parameters. In this way the influence of the mass, natural frequency and internal damping of the friction damper on the energy dissipation is established. It is shown that increasing the mass and reducing the natural frequency and internal damping of the friction damper maximizes the dissipated energy.

  • 37.
    Lopez Arteaga, Ines
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Busturia, J. M.
    Vinolas, J.
    Theoretical analysis of ring damped railway wheels2000In: Shock and Vibration Digest, ISSN 05831024 (ISSN), Vol. 32, no 1Article in journal (Refereed)
    Abstract [en]

    Ring-dampers for railway wheels can be very effective in suppressing squeal noise. An effort is made to understand the mechanisms by which damping is provided. The main aspects of wheel/ring interaction are studied in a simple single-degree-of-freedom system. A model of the nonlinear forces acting at the wheel-ring interface is developed. The large computing time needed for the time domain (TD) analysis makes it impractical to use for the parametric analysis of the wheel/ring system. Therefore, an approximate TD model is developed.

  • 38.
    Lopez Arteaga, Ines
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Busturia, J.M.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Friction dampers, the positive side of friction2004In: Proceedings of the 2004 International Conference on Noise and Vibration Engineering, ISMA / [ed] P.Sas, M. De Munck, Leuven, Belgium, 2004, p. 589-601Conference paper (Other academic)
    Abstract [en]

    Friction is frequently seen as an unwanted phenomenon whose influence has to be either minimised or controlled. In this work one of the positive sides of friction is investigated: friction damping. Friction dampers can be a cheap and efficient way to reduce the vibration levels of a wide range of mechanical systems. Here the energy dissipated through friction is analysed for a type of friction dampers used to reduce squeal noise from railway wheels. Three different 1DOF systems of increasing complexity are analytically studied and simple non-dimensional expressions are derived for the optimal friction force and energy dissipation. In this way the influence of the mass, natural frequency and internal damping of the friction damper on the energy dissipation is established. It is shown that increasing the mass and reducing the natural frequency and internal damping of the friction damper maximises the dissipated energy.

  • 39.
    Lopez Arteaga, Ines
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Hirschberg, A.
    Van Hirtum, A.
    Ruty, N.
    Pelorson, X.
    Physical modeling of buzzing artificial lips: The effect of acoustical feedback2006In: Acta Acoustica united with Acustica, ISSN 1610-1928, E-ISSN 1861-9959, Vol. 92, no 6, p. 1047-1059Article in journal (Refereed)
    Abstract [en]

    The influence of the up- and downstream acoustics on the buzzing behavior of artificial lips has been studied. In the presence of a long downstream pipe, the oscillation frequency is well predicted by means of a model assuming a single mechanical degree of freedom for the lips. A minimum of the threshold pressure for buzzing is observed when the lips are just closed at rest. The magnitude of this threshold pressure is underestimated by the model. In order to fit experiments the quality factor of the lip resonance has to be reduced by a factor two compared to the measured quality factor. In the absence of downstream pipe the threshold pressure increases by a factor three and a jump in oscillation frequency from one mechanical lip-mode to another one is observed as the lung pressure is increased. An attempt to describe this behavior by means of a 2-mass-model fails.

  • 40.
    Lopez Arteaga, Ines
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Kersjes, S.H.M.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Schmeitz, A.J.C.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Green's functions for a rotating tire: a semi-analytical approach2006Conference paper (Other academic)
  • 41.
    Lopez Arteaga, Ines
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Luiten, T.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Viscoelastic contact model for the prediction of tire/road contact forces and rolling resistance2011In: 18th International Congress on Sound and Vibration 2011, ICSV 2011, 2011Conference paper (Other academic)
    Abstract [en]

    A combined Hertz/Maxwell model is presented to approximately describe the interaction between a rigid indenter and a viscoelastic half-space, and therefore the force-indentation relationship including the deformation rate and energy losses. Thismodel is a numerically efficient alternative to the exact viscoelastic half-space formulation, to be implemented in a tyre/road interaction model for the prediction of tyre vibrations, rolling resistance and noise. Here the combined Hertz/Maxwell model is used to assess the influence of road texture on the contact stiffness and damping based on the analysis of 30 road surface types. The parameters of this model are obtained by fitting the load-penetration curves obtained from the exact viscoelastic half-space calculation. It is shown that both the stiffness and damping parameters decrease as the road texture depth increases, since, for a given penetration depth, the effective contact area decreases as the road texture depth increases. Assessing the relevance of these effects for the accurate prediction of tyre/road interaction is subject of ongoing work.

  • 42.
    Lopez Arteaga, Ines
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Mokhtari, Milad
    Moers, Elise
    Scholte, Rick
    Nijmeijer, Henk
    Vibration detection by means of NAH in the presence of reflective surfaces2012In: NOVEM 2012, 2012Conference paper (Other academic)
  • 43.
    Lopez Arteaga, Ines
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    How important is the friction model on the modeling of energy dissipation2005In: ENOC-2005 / [ed] : D.H. van Campen, M.D. Lazurko, W.P.J.M. van den Oever, Eindhoven, Netherlands, 2005, p. 363-368Conference paper (Other academic)
  • 44.
    Lopez Arteaga, Ines
    et al.
    Eindhoven University of Technology.
    Nijmeijer, H.
    Prediction and validation of the energy dissipation of a friction damper2009In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 328, no 4-5, p. 396-410Article in journal (Refereed)
    Abstract [en]

    Friction dampers can be a cheap and efficient way to reduce the vibration levels of a wide range of mechanical systems. In the present work it is shown that the maximum energy dissipation and corresponding optimum friction force of friction dampers with stiff localized contacts and large relative displacements within the contact, can be determined with sufficient accuracy using a dry (Coulomb) friction model. Both the numerical calculations with more complex friction models and the experimental results in a laboratory test set-up show that these two quantities are relatively robust properties of a system with friction. The numerical calculations are performed with several friction models currently used in the literature. For the stick phase smooth approximations like viscous damping or the arctan function are considered but also the non-smooth switch friction model is used. For the slip phase several models of the Stribeck effect are used. The test set-up for the laboratory experiments consists of a mass sliding on parallel ball-bearings, where additional friction is created by a sledge attached to the mass, which is pre-stressed against a friction plate. The measured energy dissipation is in good agreement with the theoretical results for Coulomb friction.

  • 45.
    Lopez Arteaga, Ines
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Blom, R.E.A.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Modeling the vibrations of a rotating tire: a modal approach2005In: Forum Acusticum 2005, 2005Conference paper (Other academic)
  • 46.
    Lopez Arteaga, Ines
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Scholte, R.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Assessment of Linear Predictive Border-padding for PNAH2009In: Proceedings of the 16th International Congress on Sound and Vibration, 2009Conference paper (Other academic)
    Abstract [en]

    Linear Predictive Border Padding (LPBP) is a recently presented aperture extrapolation technique to extend the applicability of PNAH to small spatial apertures (compared to the source size). Although Planar Near-field Acoustic Holography (PNAH) is recognized as a powerful and extremely fast acoustic imaging method, small measurement apertures over a portion of larger source structures lead to significant and often intolerable errors in the acoustic source images. In this paper an assessment of the accuracy of Linear Predictive Border Padding (LPBP) applied to Planar Near-field Acoustic Holography (PNAH) is presented based onnumerical experiments on two different source types: modal patterns and point sources. These two types of sources represent the two limit situations that one can find in practice: modal patterns have a tonal spectrum in the spatial wave-number domain and are relatively easy to reconstruct accurately, while point sources have a broad-band wave-number spectrum which makes them very challenging to reconstruct. For a given distance to the source, the position and size of the hologram plane apertures is varied. The reconstructed source information is compared to the reference source reconstruction obtained using a large aperture. The same analysis is also carried out with state-of-the-art aperture extrapolation methods. The reconstructed sources are compared both qualitatively (visual comparison) and quantitatively (RMS reconstruction error). The results show that LPBP is a fast, efficient and accurate extrapolation method, which leads to accurate reconstructions even for very small aperture sizes.

  • 47.
    Lopez Arteaga, Ines
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Scholte, R.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Linear Predictive Border-padding for PNAH: influence of aperture size and filter order2009In: Proceedings of Euronoise 2009, 2009Conference paper (Other academic)
    Abstract [en]

    Linear Predictive Border Padding (LPBP) is a recently presented aperture extrapolation technique [1] to extend the applicability of PNAH to small spatial apertures (compared to the source size). Although Planar Near-field Acoustic Holography (PNAH) is recognized as a powerful and extremely fast acoustic imaging method, small measurement apertures over a portion of larger source structures lead to significant and often intolerable errors in the acoustic source images. The strategy presented in [1] to pre-process the spatial acoustic data before applying FFT is robust and minimizes leakage and distortion of the acoustic field. The filter order determines the wave-number content of the extrapolated data and affects the accuracy of the reconstruction. In this paper the influence of the aperture size and filter order on the accuracy of LPBP is studied based on numerical examples and measurements on a hard disk drive and a cooling fan. The reconstructed source information is compared to the reference source reconstruction obtained using a large aperture. The reconstructed sources are compared both qualitatively (visual comparison) and quantitatively (RMS reconstruction error). The results show that LPBP is a fast and efficient extrapolation method, which leads to accurate reconstructions even for very small aperture sizes. The optimal filter order is depends on the SNR and particular source measured, but in practical situations a filter order between 5-10 should lead to adequate reconstructions.

  • 48.
    Lopez Arteaga, Ines
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Scholte, Rick
    Sorama BV.
    Nijmeijer, Henk
    Eindhoven University of Technology.
    Improved source reconstruction in Fourier-based Near-field Acoustic Holography applied to small apertures2012In: Mechanical systems and signal processing, ISSN 0888-3270, E-ISSN 1096-1216, Vol. 32, p. 359-373Article in journal (Refereed)
    Abstract [en]

    It is well known that Fourier-based Near-field Acoustic Holography fails to produce good source reconstructions when the aperture size of the microphone array is smaller than the source size. In this paper this problem is overcome by pre-conditioning the spatial hologram data using Linear Predictive Border Padding (LPBP) before it is Fourier-transformed to the wave-number domain. It is shown that LPBP allows for very small aperture sizes with a good reconstruction accuracy. An exhaustive analysis of LPBP is presented based on numerical experiments and measured data. The numerical experiments are performed on two different source types: modal patterns and point sources. These two types of sources represent the two limit situations that one can find in practice: modal patterns have a tonal spectrum in the spatial wave-number domain and are relatively easy to reconstruct accurately, while point sources have a broad-band wave-number spectrum which makes them very challenging to reconstruct. In order to illustrate the accuracy of the method in practice, results of measurements on a hard disk drive are presented as well. For a given distance to the source, the position and size of the hologram plane apertures is varied and the reconstructed source information is compared to the original source data. The reconstructed sources are compared both qualitatively and quantitatively. The results show that LPBP is an efficient and accurate extrapolation method, which leads to accurate reconstructions even for very small aperture sizes.

  • 49.
    Lopez Arteaga, Ines
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    van der Steen, R.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Schmeitz, A.J.C.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Influence of vehicle dynamics and road unevenness on tire/road contact forces for lifetime predictions2008In: Proceedings of CROW Infradagen 2008, 2008Conference paper (Other academic)
  • 50.
    Lopez Arteaga, Ines
    et al.
    Eindhoven University of Technology.
    van Doorn, R. R. J. J.
    van der Steen, R.
    Roozen, N. B.
    Nijmeijer, H.
    Frequency loci veering due to deformation in rotating tyres2009In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 324, no 3-5, p. 622-639Article in journal (Refereed)
    Abstract [en]

    This paper shows that the eigenfrequencies of a deformed tyre exhibit a mutual repulsion behaviour if the rotation velocity is increased. This phenomenon is known as frequency loci veering and is induced by the a-periodicity resulting from the tyre deformation due to the weight of the car. The corresponding eigenmodes interact in the transition zones and finally interchange. This is not the case for the undeformed tyre, where it is well known that rotation splits the eigenfrequencies around the eigenfrequencies of the non-rotating tyre. The change in eigenfrequencies is linearly related to the rotation velocity and is determined by the circumferential wavenumber and tyre radius only. For the undeformed tyre no modal interaction occurs as a consequence of rotation. Furthermore, modal interaction increases as tyre load increases and decreases as material damping increases. In previous work a methodology to model tyre vibrations has been developed, exploiting a modal base determined in a standard FE package and including rotational effects by a coordinate transformation. Major advantages of this approach are that the complex build-up of a tyre is retained and that the large (nonlinear) deformations and small (linear) vibrations are treated separately. In the present paper, the effects of deformation on the eigenfrequencies of a rotation tyre are examined using this methodology.

123 1 - 50 of 108
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf