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Publications (10 of 14) Show all publications
Gevari, M. T., Abbasiasl, T., Niazi, S., Ghorbani, M. & Kosar, A. (2020). Direct and indirect thermal applications of hydrodynamic and acoustic cavitation: A review. Applied Thermal Engineering, 171, Article ID 115065.
Open this publication in new window or tab >>Direct and indirect thermal applications of hydrodynamic and acoustic cavitation: A review
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2020 (English)In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 171, article id 115065Article, review/survey (Refereed) Published
Abstract [en]

The phase change phenomenon in fluids as a result of low local pressure under a critical value is known as cavitation. Acoustic wave propagation or hydrodynamic pressure drop of the working fluid are the main reasons for inception of this phenomenon. Considering the released energy from the collapsing cavitation bubbles as a reliable source has led to its implementation to different fields, namely, heat transfer, surface cleaning and fouling, water treatment, food industry, chemical reactions, energy harvesting. A considerable amount of energy in the mentioned industries is required for thermal applications. Cavitation could serve for minimizing the energy demand and optimizing the processes. Thus, the energy efficiency of the systems could be significantly enhanced. This review article focuses on the direct and indirect thermal applications of hydrodynamic and acoustic cavitation. Relevant studies with emerging applications are discussed, while developments in cavitation, which have given rise to thermal applications during the last decade, are also included in this review.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Hydrodynamic cavitation, Acoustic cavitation, Heat transfer enhancement, Water treatment, Food industry
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-272879 (URN)10.1016/j.applthermaleng.2020.115065 (DOI)000525326400015 ()2-s2.0-85079364402 (Scopus ID)
Note

QC 20200601

Available from: 2020-06-01 Created: 2020-06-01 Last updated: 2020-06-01Bibliographically approved
Abbasiasl, T., Niazi, S., Sheibani Aghdam, A., Chen, H., Cebeci, F. C., Ghorbani, M., . . . Kosar, A. (2020). Effect of intensified cavitation using poly (vinyl alcohol) microbubbles on spray atomization characteristics in microscale. AIP Advances, 10(2)
Open this publication in new window or tab >>Effect of intensified cavitation using poly (vinyl alcohol) microbubbles on spray atomization characteristics in microscale
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2020 (English)In: AIP Advances, ISSN 2158-3226, E-ISSN 2158-3226, Vol. 10, no 2Article in journal (Refereed) Published
Abstract [en]

In this study, cavitating flows inside a transparent cylindrical nozzle with an inner diameter of 0.9 mm were visualized, and the effect of cavitation on atomization characteristics of emerging sprays was investigated. Different patterns of cavitating flows inside the nozzle were visualized using a high-speed camera. In-house codes were developed to process the captured images to study the droplet size distribution and droplet velocity in different flow regimes. The results show that cavitating flows at the microscale have significant effects on atomization characteristics of the spray. Two working fluids, namely, water and poly(vinyl alcohol) microbubble (PVA MB) suspension, were employed. Accordingly, the injection pressures were detected as 690 kPa, 1035 kPa, and 1725 kPa for cavitation inception, supercavitation, and hydraulic flip flow regimes in the case of water, respectively. The corresponding pressures for the aforementioned patterns for PVA MB suspension were 590 kPa, 760 kPa, and 1070 kPa, respectively. At the microscale, as a result of a higher volume fraction of cavitation bubbles inside the nozzle, there is no large difference between the cavitation numbers corresponding to cavitating and hydraulic flip flows. Although the percentage of droplets with diameters smaller than 200 μm was roughly the same for both cases of water and PVA MB suspension, the Sauter mean diameter was considerably lower in the case of PVA MBs. Moreover, higher droplet velocities were achieved in the case of PVA MBs at lower injection pressures.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2020
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-268892 (URN)10.1063/1.5142607 (DOI)2-s2.0-85079560874 (Scopus ID)
Note

QC 20200226

Available from: 2020-02-25 Created: 2020-02-25 Last updated: 2020-03-16Bibliographically approved
Gevari, M. T., Shafaghi, A. H., Villanueva, L. G., Ghorbani, M. & Kosar, A. (2020). Engineered Lateral Roughness Element Implementation and Working Fluid Alteration to Intensify Hydrodynamic Cavitating Flows on a Chip for Energy Harvesting. Micromachines, 11(1), Article ID 49.
Open this publication in new window or tab >>Engineered Lateral Roughness Element Implementation and Working Fluid Alteration to Intensify Hydrodynamic Cavitating Flows on a Chip for Energy Harvesting
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2020 (English)In: Micromachines, ISSN 2072-666X, E-ISSN 2072-666X, Vol. 11, no 1, article id 49Article in journal (Refereed) Published
Abstract [en]

Hydrodynamic cavitation is considered an effective tool to be used in different applications, such as surface cleaning, ones in the food industry, energy harvesting, water treatment, biomedical applications, and heat transfer enhancement. Thus, both characterization and intensification of cavitation phenomenon are of great importance. This study involves design and optimization of cavitation on chip devices by utilizing wall roughness elements and working fluid alteration. Seven different microfluidic devices were fabricated and tested. In order to harvest more energy from cavitating flows, different roughness elements were used to decrease the inlet pressure (input to the system), at which cavitation inception occurs. The implemented wall roughness elements were engineered structures in the shape of equilateral triangles embedded in the design of the microfluidic devices. The cavitation phenomena were also studied using ethanol as the working fluid, so that the fluid behavior differences in the tested cavitation on chip devices were explained and compared. The employment of the wall roughness elements was an effective approach to optimize the performances of the devices. The experimental results exhibited entirely different flow patterns for ethanol compared to water, which suggests the dominant effect of the surface tension on hydrodynamic cavitation in microfluidic channels.

Place, publisher, year, edition, pages
MDPI, 2020
Keywords
cavitation on chip, energy harvesting, optimization, parametric effect study, hydrodynamic cavitation, microfluidics
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-269494 (URN)10.3390/mi11010049 (DOI)000514309100049 ()31906037 (PubMedID)2-s2.0-85079046940 (Scopus ID)
Note

QC 20200309

Available from: 2020-03-09 Created: 2020-03-09 Last updated: 2020-03-09Bibliographically approved
Gevari, M. T., Parlar, A., Torabfam, M., Kosar, A., Yuce, M. & Ghorbani, M. (2020). Influence of Fluid Properties on Intensity of Hydrodynamic Cavitation and Deactivation of Salmonella typhimurium. Processes, 8(3), Article ID 326.
Open this publication in new window or tab >>Influence of Fluid Properties on Intensity of Hydrodynamic Cavitation and Deactivation of Salmonella typhimurium
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2020 (English)In: Processes, ISSN 2227-9717, Vol. 8, no 3, article id 326Article in journal (Refereed) Published
Abstract [en]

In this study, three microfluidic devices with different geometries are fabricated on silicon and are bonded to glass to withstand high-pressure fluid flows in order to observe bacteria deactivation effects of micro cavitating flows. The general geometry of the devices was a micro orifice with macroscopic wall roughness elements. The width of the microchannel and geometry of the roughness elements were varied in the devices. First, the thermophysical property effect (with deionized water and phosphate-buffered saline (PBS)) on flow behavior was revealed. The results showed a better performance of the device in terms of cavitation generation and intensity with PBS due to its higher density, higher saturation vapor pressure, and lower surface tension in comparison with water. Moreover, the second and third microfluidic devices were tested with water and Salmonella typhimurium bacteria suspension in PBS. Accordingly, the presence of the bacteria intensified cavitating flows. As a result, both devices performed better in terms of the intensity of cavitating flow with the presence of bacteria. Finally, the deactivation performance was assessed. A decrease in the bacteria colonies on the agar plate was detected upon the tenth cycle of cavitating flows, while a complete deactivation was achieved after the fifteenth cycle. Thus, the proposed devices can be considered as reliable hydrodynamic cavitation reactors for "water treatment on chip" applications.

Place, publisher, year, edition, pages
MDPI, 2020
Keywords
hydrodynamic cavitation, water treatment, bacteria deactivation, Salmonella typhimurium, microfluidics
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-272883 (URN)10.3390/pr8030326 (DOI)000525842000071 ()2-s2.0-85081960633 (Scopus ID)
Note

QC 20200601

Available from: 2020-06-01 Created: 2020-06-01 Last updated: 2020-06-01Bibliographically approved
Ghorbani, M., Svagan, A. J. & Grishenkov, D. (2020). Targeted Hydrodynamic Cavitating Flows via Ultrasound Waves via Pickering Stabilized Perfluorodroplets. In: : . Paper presented at The 25th European symposium on Ultrasound Contrast Imaging.
Open this publication in new window or tab >>Targeted Hydrodynamic Cavitating Flows via Ultrasound Waves via Pickering Stabilized Perfluorodroplets
2020 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-268893 (URN)
Conference
The 25th European symposium on Ultrasound Contrast Imaging
Note

QC 20200226

Available from: 2020-02-25 Created: 2020-02-25 Last updated: 2020-02-26Bibliographically approved
Aghdam, A. S., Ghorbani, M., Deprem, G., Cebeci, F. C. & Kosar, A. (2019). A New Method for Intense Cavitation Bubble Generation on Layer-by-Layer Assembled SLIPS. Scientific Reports, 9, Article ID 11600.
Open this publication in new window or tab >>A New Method for Intense Cavitation Bubble Generation on Layer-by-Layer Assembled SLIPS
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2019 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 11600Article in journal (Refereed) Published
Abstract [en]

The importance of surface topology for the generation of cavitating flows in micro scale has been emphasized during the last decade. In this regard, the utilization of surface roughness elements is not only beneficial in promoting mass transportation mechanisms, but also in improving the surface characteristics by offering new interacting surface areas. Therefore, it is possible to increase the performance of microfluidic systems involving multiphase flows via modifying the surface. In this study, we aim to enhance generation and intensification of cavitating flows inside microfluidic devices by developing artificial roughness elements and trapping hydrophobic fluorinated lubricants. For this, we employed different microfluidic devices with various hydraulic diameters, while roughness structures with different lengths were formed on the side walls of microchannel configurations. The surface roughness of these devices was developed by assembling various sizes of silica nanoparticles using the layer-by-layer technique (D2). In addition, to compare the cavitating flow intensity with regular devices having plain surfaces (D1), highly fluorinated oil was trapped within the pores of the existing thin films in the configuration D2 via providing the Slippery Liquid-Infused Porous Surface (D3). The microfluidic devices housing the short microchannel and the extended channel were exposed to upstream pressures varying from 1 to 7.23 MPa. Cavitation inception and supercavitation condition occured at much lower upstream pressures for the configurations of D2 and D3. Interestingly, hydraulic flip, which rarely appears in the conventional conical nozzles at high pressures, was observed at moderate upstream pressures for the configuration D2 proving the air passage existence along one side of the channel wall.

Place, publisher, year, edition, pages
Nature Publishing Group, 2019
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:kth:diva-257442 (URN)10.1038/s41598-019-48175-4 (DOI)000480384500016 ()31406263 (PubMedID)2-s2.0-85070882610 (Scopus ID)
Note

QC 20190830

Available from: 2019-08-30 Created: 2019-08-30 Last updated: 2019-08-30Bibliographically approved
Ghorbani, M., Svagan, A. J. & Grishenkov, D. (2019). Acoustic Response of a Novel Class of Pickering Stabilized Perfluorodroplets. In: : . Paper presented at 24th European symposium on Ultrasound Contrast Imaging.
Open this publication in new window or tab >>Acoustic Response of a Novel Class of Pickering Stabilized Perfluorodroplets
2019 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Introduction

Acoustic Droplet Vaporization (ADV) is a phase change phenomenon in which the liquid state, in the form of droplets, is converted to gas as a result of bursts in the excited ultrasound field. Having a wide range of medical applications, ADV has drawn considerable attention in imaging [1], diagnosis and critical medical treatment [2]. Therefore, benefitting from its broad potentials, with the consideration of its capability in localized noninvasive energy exposure, it is possible to utilize its effect in different medical applications from targeted drug delivery [3] to embolotherapy [4].

Apart from the droplet characterization and ADV effectiveness on the applied region, the physics of ADV and particularly the ultrasound analysis is an essential parameter in the initiation of the vaporization. This part, which is related to acoustic wave physics, implies that ADV is mostly dependent on ultrasound pressure, frequency and temperature. In this sense, Miles et al. [5] tried to find incident negative pressure - called as ADV threshold- which is necessary for the induction of nucleation. It was successfully shown that the negative pressure required for the nucleation prior to collapse can be determined via perturbation analysis of a compressible inviscid flow around a droplet for various frequencies and diameters. In addition, the fluid medium which constitutes the droplet emulsion and the surrounding fluid constructs a significant field within ADV. In this regard, there are many studies which illustrated that the diameter of the droplets subjected to the acoustic waves undergoes a significant expansion of 5 to 6 times of their regular sizes [6-8].

In this study, a new type of pickering stabilized perfluorodroplets (PFC) was examined under the effect of the different acoustic parameters to evaluate its potential in the acoustic droplet vaporization process. To assess the pressure effects on the stabilized droplets, the acoustic power within the ultrasound tests was varied and the phase trasnition was characterized according to the experimental conditions. Opticell® was utilized as the transparent device to visualize the droplets, which were exposed to the acoustic waves with the aid of the microscope and multi-well microplate.

Methods

Materials and emulsion preparation

Perfluoropentane (PFC5) was purchased from Apollo Scientific (City, U.K.). Bleached sulfite pulp (from Nordic Paper Seffle AB, Sweden) was used in the production of the cationic cellulose nanofibers (CNFs). The CNF suspension (1.32 wt%) were prepared as described previously [9]. The CNFs had a dimension of 3.9 ± 0.8 nm in width and a length in the micrometer range. The amount of cationic groups was 0.13 mmol per g fiber, obtained from conductometric titration [9]. A suspension of CNF (0.28 wt%) was prepared by diluting the stock CNF with MilliQ-water (pH of diluted CNF suspension was 9.5). The suspension was treated with ultra-sonication at amplitude of 90% for 180 s (Sonics, Vibracell W750). The suspension was brought to room temperature. An amount of 36 g of the 0.28 wt% CNF suspension was mixed with 1 g of PFC5. The mixture was sonicated for 60s at an amplitude of 80% (under ice-cooling) to obtain the CNF-stabilized PFC5 droplets.

The protocol for the acoustic tests

100 μL of CNF-stabilized PFC5 droplets were added to 1900 μL of deionized water in order to prepare the solution which were exposed to the ultrasound waves. The droplet sample, diluted 1:19 in distilled water was introduced to the Opticell® and the acoustic waves at a fixed frequency and different powers were applied to the trageted area inside the Opticell® which is located inside a water bath. The ultrasound triggered sample then was placed under a 20X magnification objective of upright transmitted light microscope (ECLIPSE Ci-S, Nikon, Tokyo, Japan). 

The acoustic tests were performed using high-power tone burst pulser-receiver (SNAP Mark IV,  Ritec, Inc., Warwick, RI, USA) equipped with a transducer (V382-SU Olympus NDT, Waltham, MA ) operating at the frequency of 3.5 MHz. The emulsion of CNF-stabilized PFC5 droplets were exposed to the power range which has the acsending trend from -30 to 0 dB at the given frequency. To investigate the droplet size variations at each power between, the droplets were collected inside the Opticell® and the droplet diameter was measured with the aid of the ImageJ software (version 1.50b, National institutes of health, USA) to determine the concentration and size distribution. The Gaussian distribution is ploted with mean value and standad deviation recover from the experimental data. An in-house image edge detection MATLAB™ script (MathWorks Inc., Natick, MA) were applied to analyze the images obtained from the microscope and provides the size and volume distributions.

Results

The size of PFP droplets is an important parameter to controll in the therapeutic applications. Here, a new type of Pickering stabilized perfluorodroplets were prepared where the PFP/water interface was stabilized with cellulose nanofibers (CNF) and the size of the droplets could easily be controlled by varying the amount of CNF added.  The resulting droplets were investigated using a single crystal transducer. Apart from the medical applications, controlling the droplet size is important from droplet dynamics point of view, becausethe interfacial energy is crucial in the assumption of the critical nucleus radius. Therefore, it is possible to estimate the negative peak pressure required for the phase transition once the droplet is controlled and interfacial energy deposited inside and on the surface of the droplet are balanced.

According to the results in Figure 1, there is an appreciable rise of the size of the droplets after ultrasound waves exposure, particularly at -8 dB power. The experiments were performed for 30 seconds at different powers ranging from -30 to 0 dB, while the frequency was kept constant at 3.5 MHz, burst width in cycles was selected as 12 and repetition rate was set to 100. Images included in Figure 1 demonstrate major transitions in the intervals at -16, -8 and 0 dB. As shown in this figure, the droplet size increased with the power rise and more bubbles with bigger sizes appears at higher powers. This outcome implies the significant role of the applied frequency and power on the phase shift and subsequent mechanisms as a result of the acoustic wave exposure on the new nontoxic and incompatible droplet type.

Figure 2 shows the average number of droplets and volume distribution at the corresponding powers to the Figure 1. It is shown that while the average diameter of the droplets is around 3.5 µm, the generated bubbles, as a result of the ADV, reaches up to 15 µm at the highest possible power. For each set of experiment (corresponding to a given power) 32 images were taken, thus, to reduce the errors and obtain the standard deviation (approximately 0.8 for all the cases), the presented diagrams for the droplet distributions exhibits the mean value for all of the acquired images. Therefore, it is shown that the droplet emulsion exhibited in NO US in Figure 2, which shows the regular view and distribution range of the CNF-stabilized PFC5 droplets at the room temperature, experiences ADV process with the diameter rise of about 5 times at the highest power when the frequency is fixed at 3.5 MHz.

Conclusions

The results show that there is appreciable rise on the size of the droplets after ultrasound waves exposure at a fixed frequency. Acoustic droplet vaporization (ADV) was illustrated at different powers for CNF-stabilized PFC5 droplets as a new class of pickering stabilized perfluorodroplets with the increase in the size of the droplets and following phase trasition to bubbles. Diameter increase of 5 times were obtained after the ultrasound exposure indicating the efficiency of the suggested droplets for the ADV process and therapeutic applications.   

References

[1] Arena CB, Novell A, Sheeran PS, Puett C, Moyer LC, Dayton PA, Dual-Frequency Acoustic Droplet Vaporization Detection for Medical Imaging 2015, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 62: 9.

[2] Kripfgans OD, Fowlkes JB, Miller DL, Eldevik OP, Carson PL, Acoustic droplet vaporization for therapeutic and diagnostic applications 2000, Ultrasound Med. Biol, 26:1177–1189.

[3] Kang ST, Yeh CK, Intracellular Acoustic Droplet Vaporization in a Single Peritoneal Macrophage for Drug Delivery Applications 2011, Langmuir, 27:13183–13188.

[4] Zhu M, Jiang L, Fabiilli ML, Zhang A, Fowlkes JB, Xu LX, Treatment of murine tumors using acoustic droplet vaporization-enhanced high intensity focused 2013, Ultrasound Phys. Med. Biol, 58:6179–6191.

[5] Miles CJ, Doering CR, Kripfgans OD, Nucleation pressure threshold in acoustic droplet vaporization 2016, Journal of Applied Physics, 120:034903.

[6] Sheeran PS, Wong VP, Luois S, McFarland RJ, Ross WD, Feingold S, Matsunaga TO, Dayton PA, Decafluorobutane as a phase-change contrast agent for low-energy extravascular ultrasonic imaging 2011, Ultrasound Med. Biol, 37:1518–1530.

[7] Kripfgans OD, Fowlkes JB, Miller DL, Eldevik OP, Carson PL, Acoustic droplet vaporization for therapeutic and diagnostic applications 2000, Ultrasound Med. Biol, 26:1177–1189.

[8] Kang S, Huang Y, Yeh C, Characterization of acoustic droplet vaporization for control of bubble generation under flow conditions 2014, Ultrasound Med. Biol, 40:551–561.

[9] Svagan AJ, Benjamins JW, Al-Ansari Z, Shalom DB, Müllertz A, Wågberg L, Löbmann K, Solid cellulose nanofiber based foams–towards facile design of sustained drug delivery systems 2016, J. Control Release, 244:74–82 (Part A).

 

National Category
Natural Sciences Other Physics Topics Biomaterials Science
Research subject
Medical Technology
Identifiers
urn:nbn:se:kth:diva-239309 (URN)
Conference
24th European symposium on Ultrasound Contrast Imaging
Note

QC 20190319

Available from: 2018-11-20 Created: 2018-11-20 Last updated: 2019-03-19Bibliographically approved
Talebian Gevari, M., Ghorbani, M., J. Svagan, A., Grishenkov, D. & Kosar, A. (2019). Energy harvesting with micro scale hydrodynamic cavitation-thermoelectric generation coupling. AIP Advances
Open this publication in new window or tab >>Energy harvesting with micro scale hydrodynamic cavitation-thermoelectric generation coupling
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2019 (English)In: AIP Advances, ISSN 2158-3226, E-ISSN 2158-3226Article in journal (Refereed) Published
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-261404 (URN)
Note

QC 20191011

Available from: 2019-10-06 Created: 2019-10-06 Last updated: 2019-10-11Bibliographically approved
Talebian Gevari, M., Ghorbani, M., Svagan, A. J., Grishenkov, D. & Kosar, A. (2019). Energy harvesting with micro scale hydrodynamic cavitation-thermoelectric generation coupling. AIP Advances, 9, Article ID 105012.
Open this publication in new window or tab >>Energy harvesting with micro scale hydrodynamic cavitation-thermoelectric generation coupling
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2019 (English)In: AIP Advances, ISSN 2158-3226, E-ISSN 2158-3226, Vol. 9, article id 105012Article in journal (Refereed) Published
Abstract [en]

In this study, energy harvesting with micro scale hydrodynamic cavitation-thermoelectric generation coupling is investigated. For this, three micro orifices with different geometrical dimensions are fabricated. The hydraulic diameter of the micro orifices are 66.6 mu m, 75.2 mu m, and 80 mu m, while their length is the same (2000 mu m). Two different working fluids, namely water and Perfluoropentane droplet-water suspension, are utilized for cavitating flows in the fabricated micro orifices. The flow patterns at different upstream pressures are recorded using the high-speed camera system, and the experimental results are analyzed and compared. Thereafter, energy harvesting perspectives of cavitating flows are considered. The released heat from collapsing bubbles and the subsequent temperature rise on the end wall of the microchannel, which can be used as the source for the power generation, is calculated over time. Finally, a miniature energy harvesting system with cavitation system and thermoelectric generator coupling is presented. The maximum power corresponding to two different thermoelectric generators is estimated for with both working fluids and is compared with the required power to run miniature daily used electronics components.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-261422 (URN)10.1063/1.5115336 (DOI)000496806000013 ()2-s2.0-85073407537 (Scopus ID)
Note

QC 20191011. QC 20200217

Available from: 2019-10-07 Created: 2019-10-07 Last updated: 2020-02-17Bibliographically approved
Ghorbani, M., Araz, S. A., Talebian, M., Kosar, A., Cakmak Cebeci, F., Grishenkov, D. & Svagan, A. J. (2019). Facile Hydrodynamic Cavitation ON CHIP via Cellulose Nanofibers Stabilized Perfluorodroplets inside Layer-by-Layer Assembled SLIPS Surfaces. Chemical Engineering Journal
Open this publication in new window or tab >>Facile Hydrodynamic Cavitation ON CHIP via Cellulose Nanofibers Stabilized Perfluorodroplets inside Layer-by-Layer Assembled SLIPS Surfaces
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2019 (English)In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212Article in journal (Refereed) Published
Abstract [en]

The tremendous potential of “hydrodynamic cavitation on microchips” has been highlighted during recent years in various applications. Cavitating flow patterns, substantially depending upon thermophysical and geometrical characteristics, promote diverse industrial and engineering applications, including food and biomedical treatment. Highly vaporous and fully developed patterns in microfluidic devices are of particular interest. In this study, the potential of a new approach, which includes cellulose nanofiber (CNF)- stabilized perfluorodroplets (PFC5s), was assessed inside microfluidic devices. The surfaces of these devices were modified by assembling various sizes of silica nanoparticles, which facilitated in the generation of cavitation bubbles. To examine the pressure effects on the stabilized droplets in the microfluidic devices, the upstream pressure was varied, and the cavitation phenomenon was characterized under different experimental conditions. The results illustrate generation of interesting, fully developed, cavitating flows at low pressures for the stabilized droplets, which has not been previously observed in the literature. Supercavitation flow pattern, filling the entire microchannel, were recorded at the upstream pressure of 1.7 MPa for the case of CNF-stabilized PFC5s, which hardly corresponds to cavitation inception for pure water in the same microfluidic device.

Place, publisher, year, edition, pages
Elsevier, 2019
National Category
Chemical Process Engineering Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-259752 (URN)10.1016/j.cej.2019.122809 (DOI)000503381200101 ()2-s2.0-85072956974 (Scopus ID)
Note

QC 20190913

Available from: 2019-09-23 Created: 2019-09-23 Last updated: 2020-03-09Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4883-7347

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