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Measurement-Integrated simulations and Kalman filter applied to a co-flowing jet
KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
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2010 (English)In: 5th Flow Control Conference, 2010, 2010-4420- p.Conference paper (Refereed)
Abstract [en]

This paper deals with the experimental evaluation of a flow analysis system based on the integration between an under-resolved Navier-Stokes simulation and experimental measurements with the mechanism of feedback (referred to as Measurement-Integrated simulation), applied to the case of a planar turbulent co-flowing jet. The experiments are performed with inner-to-outer-jet velocity ratio around 2 and the Reynolds number based on the inner-jet heights about 10000. The measurement system is a high-speed PIV, which provides time-resolved data of the flow-field, on a field of view which extends to 20 jet heights downstream the jet outlet. The experimental data can thus be used both for providing the feedback data for the simulations and for validation of the MI-simulations over a wide region. The effect of reduced data-rate and spatial extent of the feedback (i.e. measurements are not available at each simulation time-step or discretization point) was investigated. At first simulations were run with full information in order to obtain an upper limit of the MI-simulations performance. The results show the potential of this methodology of reproducing first and second order statistics of the turbulent flow with good accuracy. Then, to deal with the reduced data different feedback strategies were tested. It was found that for small data-rate reduction the results are basically equivalent to the case of full-information feedback but as the feedback data-rate is reduced further the error increases and tend to be localized in regions of high turbulent activity. Moreover, it is found that the spatial distribution of the error looks qualitatively different for different feedback strategies. Feedback gain distributions calculated by optimal control theory are presented and proposed as a mean to make it possible to perform MI-simulations based on localized measurements only. So far, we have not been able to low error between measurements and simulations by using these gain distributions.

Place, publisher, year, edition, pages
2010. 2010-4420- p.
Keyword [en]
Data-rate, Discretizations, Experimental data, Experimental evaluation, Experimental measurements, Feedback gain, Feedback strategies, Field of views, Flow analysis, Gain distribution, High-speed, Information feedback, Jet velocities, Measurement system, Measurement-integrated simulation, Navier Stokes simulation, Optimal control theory, Reduced data, Second order statistics, Simulation time, Small data, Spatial distribution, Spatial extent, Time-resolved data, Turbulent activity, Upper limits
National Category
Applied Mechanics
URN: urn:nbn:se:kth:diva-149692ScopusID: 2-s2.0-78649493993ISBN: 978-160086745-3OAI: diva2:741511
5th Flow Control Conference; Chicago, IL; United States; 28 June 2010 through 1 July 2010

QC 20140828

Available from: 2014-08-28 Created: 2014-08-26 Last updated: 2014-08-28Bibliographically approved

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Bellani, GabrieleTammisola, OutiLundell, Fredrik
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