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Multi-Faceted Surface Effect on Heat Transfer Performance and Flow Dynamics at the Onset of Optimum Nusselt Number


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DOI: https://doi.org/10.15866/irea.v9i6.20080

Abstract


A multi-faceted cylinder of half-circle, flat, and triangle surfaces is investigated numerically in this study. The flow characteristics were observed. Their effects on thermal performance were investigated under various cross-flow conditions and blocking ratios. The multi-faceted cylinder's effectiveness compared to the circular cylinder in terms of a heat exchanger is also presented. The multi-faceted cylinder suffers an average of 0.47% drop in effectiveness relative to the circular cylinder. However, despite producing a higher heat transfer coefficient, the circular cylinder has a lower Nusselt number contributed by a higher Strouhal number. A lower Strouhal number in a multi-faceted cylinder enables it to have a higher Nusselt number in the downstream surface than the circular cylinder. This is due to better fluid contact through flow attachment at the flat surface and the sharp edge. The multi-faceted cylinder's asymmetrical surface also creates higher velocity imbalances in the upper and lower half of the channel, which produced a distinct drag coefficient pattern. The multi-faceted cylinder offers enhanced convective heat transfer compared to the circular cylinder but with relatively higher drag under increasing Reynolds number.
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Keywords


Bluff Body; Cross Flow; Circular Cylinder; Heat Transfer Coefficient; Multi-Faceted Cylinder; Modified Cylinder

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References


M. Elkhoury, Assessment of turbulence models for the simulation of turbulent flows past bluff bodies, J. Wind Eng. Ind. Aerodyn., vol. 154, pp. 10-20, 2016.
https://doi.org/10.1016/j.jweia.2016.03.011

H. Abbassi, S. Turki, and S. Ben Nasrallah, Channel flow past bluff-body: Outlet boundary condition, vortex shedding and effects of buoyancy, Comput. Mech., vol. 28, no. 1, pp. 10-16, 2001.
https://doi.org/10.1007/s004660100261

A. Sohankar, L. Davidson, and C. Norberg, Large eddy simulation of flow past a square cylinder: Comparison of different subgrid scale models, J. Fluids Eng. Trans. ASME, vol. 122, no. 1, pp. 39-47, 2000.
https://doi.org/10.1115/1.483224

J. N. Wood, G. De Nayer, S. Schmidt, and M. Breuer, Experimental Investigation and Large-Eddy Simulation of the Turbulent Flow past a Smooth and Rigid Hemisphere, Flow, Turbul. Combust., vol. 97, no. 1, pp. 79-119, 2016.
https://doi.org/10.1007/s10494-015-9690-5

S. Mittal, S. P. Singh, B. Kumar, and R. Kumar, Flow past bluff bodies: Effect of blockage, Int. J. Comut. Fluid Dyn., vol. 20, no. 3-4, pp. 163-173, 2006.
https://doi.org/10.1080/10618560600789735

T. Rasool, A. Dhiman, and M. Parveez, Cross-buoyancy mixed convection around a confined triangular bluff body, Numer. Heat Transf. Part A Appl., vol. 67, no. 4, pp. 454-475, 2015.
https://doi.org/10.1080/10407782.2014.937250

N. Varma, J. P. Dulhani, A. Dalal, S. Sarkar, and S. Ganguly, Effect of Channel Confinement on Mixed Convective Flow Past an Equilateral Triangular Cylinder, J. Heat Transfer, vol. 137, no. 12, pp. 21-26, 2015.
https://doi.org/10.1115/1.4030960

A. Sanyal and A. Dhiman, Effect of forced convection heat transfer over side-by-side square cylinders in a steady confined flow regime, J. Comput. Appl. Mech., vol. 11, no. 2, pp. 197-209, 2016.
https://doi.org/10.32973/jcam.2016.013

A. Kumar, A. Dhiman, and L. Baranyi, CFD analysis of power-law fluid flow and heat transfer around a confined semi-circular cylinder, Int. J. Heat Mass Transf., vol. 82, pp. 159-169, 2015.
https://doi.org/10.1016/j.ijheatmasstransfer.2014.11.046

S. C. Luo, M. G. Yazdani, Y. T. Chew, and T. S. Lee, Effects of incidence and afterbody shape on flow past bluff cylinders, J. Wind Eng. Ind. Aerodyn., vol. 53, no. 3, pp. 375-399, 1994.
https://doi.org/10.1016/0167-6105(94)90092-2

S. Yagmur, S. Dogan, M. H. Aksoy, E. Canli, and M. Ozgoren, Experimental and Numerical Investigation of Flow Structures around Cylindrical Bluff Bodies, EPJ Web Conf., vol. 92, pp. 3-9, 2015.
https://doi.org/10.1051/epjconf/20159202113

M. Dutka, M. Ditaranto, and T. Løvås, Investigations of air flow behavior past a conical bluff body using particle imaging velocimetry, Exp. Fluids, vol. 56, no. 11, 2015.
https://doi.org/10.1007/s00348-015-2068-6

J. P. Dulhani and A. Dalal, Flow past an equilateral triangular bluff obstacle: Computational study of the effect of thermal buoyancy on flow physics and heat transfer, Numer. Heat Transf. Part A Appl., vol. 67, no. 4, pp. 476-495, 2015.
https://doi.org/10.1080/10407782.2014.937254

T. Ambreen and M. H. Kim, Flow and heat transfer characteristics over a square cylinder with corner modifications, Int. J. Heat Mass Transf., vol. 117, pp. 50-57, 2018.
https://doi.org/10.1016/j.ijheatmasstransfer.2017.09.132

F. Zafar and M. M. Alam, Flow structure around and heat transfer from cylinders modified from square to circular, Phys. Fluids, vol. 31, no. 8, 2019.
https://doi.org/10.1063/1.5109693

R. Agarwal and A. Dhiman, Confined flow and heat transfer phenomena of non-newtonian shear-thinning fluids across a pair of tandem triangular bluff bodies, Numer. Heat Transf. Part A Appl., vol. 68, no. 2, pp. 174-204, 2015.
https://doi.org/10.1080/10407782.2014.977120

M. M. Alam, Lift forces induced by phase lag between the vortex sheddings from two tandem bluff bodies, J. Fluids Struct., vol. 65, pp. 217-237, 2016.
https://doi.org/10.1016/j.jfluidstructs.2016.05.008

F. Zafar and M. M. Alam, A low Reynolds number flow and heat transfer topology of a cylinder in a wake, Phys. Fluids, vol. 30, no. 8, 2018.
https://doi.org/10.1063/1.5035105

Z. Ghorbani-Tari, Y. Chen, and Y. Liu, Complementary temperature-sensitive paint measurements and CFD analysis of wall heat transfer of cubes-in-tandem in a turbulent channel flow, Exp. Therm. Fluid Sci., vol. 98, no. April, pp. 56-67, 2018.
https://doi.org/10.1016/j.expthermflusci.2018.05.014

W. Zhang, H. Yang, H. S. Dou, and Z. Zhu, Forced convection of flow past two tandem rectangular cylinders in a channel, Numer. Heat Transf. Part A Appl., vol. 72, no. 1, pp. 89-106, 2017.
https://doi.org/10.1080/10407782.2017.1353384

A. Sanyal and A. Dhiman, Effect of thermal buoyancy on a fluid flowing past a pair of side-by-side square bluff-bodies in a low-Reynolds number flow regime, Phys. Fluids, vol. 30, no. 6, 2018.
https://doi.org/10.1063/1.5025652

M. Furquan and S. Mittal, Flow past two square cylinders with flexible splitter plates, Comput. Mech., vol. 55, no. 6, pp. 1155-1166, 2015.
https://doi.org/10.1007/s00466-014-1110-5

F. B. Teixeira, G. Lorenzini, M. R. Errera, L. A. O. Rocha, L. A. Isoldi, and E. D. dos Santos, Constructal Design of triangular arrangements of square bluff bodies under forced convective turbulent flows, Int. J. Heat Mass Transf., vol. 126, pp. 521-535, 2018.
https://doi.org/10.1016/j.ijheatmasstransfer.2018.04.134

S. Mittal, Control Of Flow Past Bluff Bodies Using Rotating Control Cylinders, J. Fluids Struct., vol. 15, pp. 291-326, 2001, doi: 10.1006/j.
https://doi.org/10.1006/jfls.2000.0337

C. Santoni, K. Carrasquillo, I. Arenas-Navarro, and S. Leonardi, Effect of tower and nacelle on the flow past a wind turbine, Wind Energy, vol. 20, no. 12, pp. 1927-1939, 2017.
https://doi.org/10.1002/we.2130

G. Li, Y. Zheng, G. Hu, Z. Zhang, and Y. Xu, Experimental Study of the Heat Transfer Enhancement from a Circular Cylinder in Laminar Pulsating Cross-flows, Heat Transf. Eng., vol. 37, no. 6, pp. 535-544, 2016.
https://doi.org/10.1080/01457632.2015.1060758

J. Liu, S. Hussain, L. Wang, G. Xie, and B. Sundén, Effects of a pocket cavity on heat transfer and flow characteristics of the endwall with a bluff body in a gas turbine engine, Appl. Therm. Eng., vol. 143, no. August, pp. 935-946, 2018.
https://doi.org/10.1016/j.applthermaleng.2018.08.020

A. S. Ramamurthy and P. Bhaskaran, Constrained Flow Past Cavitating Bluff Bodies., Am. Soc. Mech. Eng., no. 78-WA/FE-11, 1978.

A. K. Soti, R. Bhardwaj, and J. Sheridan, Flow-induced deformation of a flexible thin structure as manifestation of heat transfer enhancement, Int. J. Heat Mass Transf., vol. 84, pp. 1070-1081, 2015.
https://doi.org/10.1016/j.ijheatmasstransfer.2015.01.048

G. T. Gargioni, P. S. B. Zdanski, and M. Vaz, Heat transfer enhancement in flow past triangular turbulence promoters in closed channels, Numer. Heat Transf. Part A Appl., vol. 75, no. 5, pp. 309-326, 2019.
https://doi.org/10.1080/10407782.2019.1582986

A. S. L. Frank P. Incropera, David P. Dewitt, Theodore L. Bergman, Principles of Heat and Mass Transfer, 7th ed. John Wiley & Sons.

N. Mahír and Z. Altaç, Numerical investigation of convective heat transfer in unsteady flow past two cylinders in tandem arrangements, Int. J. Heat Fluid Flow, vol. 29, no. 5, pp. 1309-1318, 2008.
https://doi.org/10.1016/j.ijheatfluidflow.2008.05.001

S. Chamoli, T. Tang, P. Yu, and R. Lu, Effect of shape modification on heat transfer and drag for fluid flow past a cam-shaped cylinder, Int. J. Heat Mass Transf., vol. 131, pp. 1147-1163, 2019.
https://doi.org/10.1016/j.ijheatmasstransfer.2018.11.057

K. S. Y. and D. X. H. Ding, C. Shu, Numerical simulation of flows around two circular cylinders by mesh‐free least square‐based finite difference methods, Int. J. Numer. Methods Fluids, vol. 53, no. 6 july, pp. 305-332, 2006.
https://doi.org/10.1002/fld.1281

C. Liu, X. Zheng, C. Liao, C. H. Sung, and T. T. Huang, Preconditioned multigrid methods for unsteady incompressible flows, 35th Aerosp. Sci. Meet. Exhib., vol. 57, pp. 35-57, 1997.
https://doi.org/10.2514/6.1997-445

J. Park and H. Choi, Numerical solutions of flow past a circular cylinder at reynolds numbers up to 160, KSME Int. J., vol. 12, no. 6, pp. 1200-1205, 1998.
https://doi.org/10.1007/BF02942594

L. Qu, C. Norberg, L. Davidson, S. H. Peng, and F. Wang, Quantitative numerical analysis of flow past a circular cylinder at Reynolds number between 50 and 200, J. Fluids Struct., vol. 39, pp. 347-370, 2013.
https://doi.org/10.1016/j.jfluidstructs.2013.02.007

B. N. Rajani, A. Kandasamy, and S. Majumdar, Numerical simulation of laminar flow past a circular cylinder, Appl. Math. Model., vol. 33, no. 3, pp. 1228-1247, 2009.
https://doi.org/10.1016/j.apm.2008.01.017

E.R.G. Eckert, Distribution of heat-transfer coefficients around circular cylinders in crossflow at Reynolds numbers from 20 to 500, Trans. ASME, vol. 74, pp. 343-347.

R. Senthil kumar and S. Jayavel, Influence of flow shedding frequency on convection heat transfer from bank of circular tubes in heat exchangers under cross flow, Int. J. Heat Mass Transf., vol. 105, pp. 376-393, 2017.
https://doi.org/10.1016/j.ijheatmasstransfer.2016.09.097


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