THERMAL SCIENCE

International Scientific Journal

EFFECTS OF ELASTIC PILLARS ON FLUID-FLOW AND HEAT TRANSFER ENHANCEMENT IN A MICRO-CHANNEL

ABSTRACT
In this paper, periodic vortices are generated by a fluid passing a cylindrical obstacle, d, near the micro-channel inlet. Two elastic pillars are arranged on the walls, and the effect of the pillar spacing on heat transfer performance is studied using the Arbitrary Lagrangian-Euler method. With the spacing of 10d, the small pillar amplitude of 2 μm is not conducive to the generation of vortices. The flexible vortex generator has higher heat transfer efficiency and lower pressure loss than the rigid vortex generator. The two pillars with no spacing generate isolated vortices, and the mixing of these vortices is insufficient downstream the pillars. It is found that with the pillar spacing of 5d, the overall performance factor is significantly higher than that with the pillar spacing of 0d and 10d in the Reynolds number range of 800 to 1100. The average Nusselt number with the spacing of 5d increases by 19.2% compared to that with the spacing of 0d at the Reynolds number of 1000. When the Reynolds number is 1100, the overall performance factor is 43% higher than that with a single rigid pillar. The vortices are periodically generated by the two pillars with the 5d spacing, and the disturbance to the boundary layer enhances the heat transfer downstream the region in the micro-channel.
KEYWORDS
PAPER SUBMITTED: 2022-06-17
PAPER REVISED: 2022-08-16
PAPER ACCEPTED: 2022-08-18
PUBLISHED ONLINE: 2022-09-10
DOI REFERENCE: https://doi.org/10.2298/TSCI220617139Y
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2023, VOLUME 27, ISSUE Issue 1, PAGES [275 - 287]
REFERENCES
  1. Zhou, F., et al., Experimental and Numerical Studies on Heat Transfer Enhancement of Microchannel Heat Exchanger Embedded with Different Shape Micropillars, Applied Thermal Engineering, 175(2020), pp. 115296.
  2. Ahmed, H. E., and Ahmed, M. I., Optimum Thermal Design of Triangular, Trapezoidal and Rectangular Grooved Microchannel Heat Sinks, International Communications in Heat and Mass Transfer, 66(2015), pp. 47 57.
  3. Derakhshanpour, K., et al., Effect of Rib Shape and Fillet Radius on Thermal-Hydrodynamic Performance of Microchannel Heat Sinks: A CFD Study, International Communications in Heat and Mass Transfer, 119(2020), pp. 104928.
  4. Lu, G., and Zhai, X., Analysis on Heat Transfer and Pressure Drop of a Microchannel Heat Sink with Dimples and Vortex Generators, International Journal of Thermal Sciences, 145(2019), pp. 105986.
  5. Ebrahimi, A., et al., Numerical Study of Liquid Flow and Heat Transfer in Rectangular Microchannel with Longitudinal Vortex Generators, Applied Thermal Engineering, 78(2015), pp. 576--583.
  6. Vinoth, R., and Senthil, K., Numerical Study of Inlet Cross-Section Effect on Oblique Finned Microchannel Heat Sink, Thermal Science, 22(2018), pp. 2747--2757.
  7. Wang, J., et al., Effects of Pin Fins and Vortex Generators on Thermal Performance in a Microchannel with Al2O3 Nanofluids, Energy, 239(2022), pp. 122606.
  8. Ma, T., et al., Thermal-Hydraulic Characteristics of Printed Circuit Heat Exchanger Used for Floating Natural Gas Liquefaction, Renewable and Sustainable Energy Reviews, 137(2021), pp. 110606.
  9. Lian, J., et al., Thermal and Mechanical Performance of a Hybrid Printed Circuit Heat Exchanger Used for Supercritical Carbon Dioxide Brayton Cycle, Energy Conversion and Management, 245(2021), pp. 114573.
  10. Ma, T., et al., Recent Trends on Nanofluid Heat Transfer Machine Learning Research Applied to Renewable Energy, Renewable and Sustainable Energy Reviews, 138(2021), pp. 110494.
  11. Anwar, M., et al., Numerical Study for Heat Transfer Enhancement Using CuO Water Nanofluids through Mini-Channel Heat Sinks for Microprocessor Cooling, Thermal Science, 24(2020), pp. 2965--2976.
  12. Siddiqui, A., et al., Evaluation of Nanofluids Performance for Simulated Microprocessor, Thermal Science, 21(2017), pp. 2227--2236.
  13. Fattahi, A., LBM Simulation of Thermo-Hydrodynamic and Irreversibility Characteristics of a Nanofluid in Microchannel Heat Sink under Affecting a Magnetic Field, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, (2020), pp. 1--17.
  14. Dinarvand, M., et al., Cooling Capacity of Magnetic Nanofluid in Presence of Magnetic Field Based on First and Second Laws of Thermodynamics Analysis, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, (2021), pp. 1--17.
  15. Qomi, et al., A., 2020, Heat Transfer Enhancement in a Microchannel Using a Pulsating MHD Hybrid Nanofluid Flow, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, (2020), pp. 1--16.
  16. Hosseini, S., et al., An Immersed Boundary-Lattice Boltzmann Method with Multi Relaxation Time for Solving Flow-Induced Vibrations of an Elastic Vortex Generator and Its Effect on Heat Transfer and Mixing, Chemical Engineering Journal, 405(2021), pp. 126652.
  17. Lee, J. B., et al., Heat Transfer Enhancement by Flexible Flags Clamped Vertically in a Poiseuille Channel Flow, International Journal of Heat and Mass Transfer, 107(2017), pp. 391--402.
  18. Park, S. G., Heat Transfer Enhancement by a Wall-Mounted Flexible Vortex Generator with an Inclination Angle, International Journal of Heat and Mass Transfer, 148(2020), pp. 119053.
  19. Chen, Y., et al., Heat Transfer Enhancement in a Poiseuille Channel Flow by Using Multiple Wall-Mounted Flexible Flags, International Journal of Heat and Mass Transfer, 163(2020), pp. 120447.
  20. Li, L., et al., Enhancement of Heat Transfer and Mixing with Two Side-by-Side Freely Rotatable Cylinders in Microchannel, International Journal of Heat and Mass Transfer, 189(2022), pp. 122717.
  21. Ali, S., et al., Heat Transfer and Mixing Enhancement by Using Multiple Freely Oscillating Flexible Vortex Generators, Applied Thermal Engineering, 105(2016), pp. 276--289.
  22. Shin, S., et al., Enhanced Boiling Heat Transfer Using Self-Actuated Nanobimorphs, Nano Letters, 18(2018), pp. 6392--6396.
  23. Donea, J., et al., Chapter 14: Arbitrary Lagrangian-Eulerian Methods, Encyclopedia of Computational, (2004), pp. 1--25.
  24. Tuković, Ž., and Jasak, H., Updated Lagrangian Finite Volume Solver for Large Deformation Dynamic Response of Elastic Body, Transactions of Famena, 31(2017), pp. 55--70.
  25. Karniadakis, G. E., et al., Microflows and Nanoflows: Fundamentals and Simulation, Interdisciplinary Applied Mathematics, 29(2006), pp. 1--61.
  26. Dadvand, A., et al., Enhancement of Heat and Mass Transfer in a Microchannel via Passive Oscillation of a Flexible Vortex Generator, Chemical Engineering Science, 207(2019), pp. 556--580.
  27. Celik, I. B., et al., Procedure for Estimation and Reporting of Uncertainty Due to Discretization in CFD Applications, Journal of Fluids Engineering, 130(2008), pp. 078001.

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence