Application of different CFD multiphase models to investigate effects of baffles and nanoparticles on heat transfer enhancement

Abstract

In this work, the effect of baffles in a pipe on heat transfer enhancement was studied using computational fluid dynamics (CFD) in the presence of Al₂O₃ nanoparticles which are dispersed into water. Fluid flow through the horizontal tube with uniform heat flux was simulated numerically and three dimensional governing partial differential equations were solved. To find an accurate model for CFD simulations, the results obtained by the single phase were compared with those obtained by three different multiphase models including Eulerian, mixture and volume of fluid (VOF) at Reynolds numbers in range of 600 to 3000, and two different nanoparticle concentrations (1% and 1.6%). It was found that multiphase models could better predict the heat transfer in nanofluids. The effect of baffles on heat transfer of nanofluid flow was also investigated through a baffled geometry. The numerical results show that at Reynolds numbers in the range of 600 to 2100, the heat transfer of nanofluid flowing in the geometry without baffle is greater than that of water flowing through a tube with baffle, whereas the difference between these effects (nanofluid and baffle) decreases with increasing the Reynolds number. At higher Reynolds numbers (2100–3000) the baffle has a greater effect on heat transfer enhancement than the nanofluid.

Keywords

CFD simulation / heat transfer / nanofluid / baffle / single phase model / multiphase model

References

[1] Bergles A E. Handbook of Heat Transfer. 3rd ed. New York: McGraw-Hill, 1998

[2] Bergles A E. The implications and challenges of enhanced heat transfer for the chemical process industries. Journal of Chemical Engineering Research and Design, 2001, 79(4): 437-444

[3] Choi S U S, Eastman J A. Enhancing Thermal Conductivity of Fluids with Nanoparticles. San Francisco: International Mechanical Engineering Congress and Exhibition, 1995

[4] Keblinksi P, Phillpot S R, Choi S U S, Eastman J A. Mechanisms of heat flow in suspensions of nano-sized particles (nanofluids). International Journal of Heat and Mass Transfer, 2002, 45(4): 855-863

[5] Tynjälä T. Theoretical and numerical study of thermomagnetic convection in magnetic fluids. Dissertation for the Doctoral Degree. Finland: Lappeenranta University of Technology, 2005

[6] Walde S P, Kriplani V M. Review of heat transfer enhancement in different types of baffles and their orientations. International Journal of Engineering Science and Technology, 2012, 4: 1367-1372

[7] Izadi M, Behzadmehr A, Jalali-Vahida D. Numerical study of developing laminar forced convection of a nanofluid in an annulus. International Journal of Thermal Sciences, 2009, 48(11): 2119-2129

[8] Rostamani M, Hosseinizadeh S F, Gorji M, Khodadadi J M. Numerical study of turbulent forced convection flow of nanofluids in a long horizontal duct considering variable properties. International Communications in Heat and Mass Transfer, 2010, 37(10): 1426-1431

[9] Ghaffari O, Behzadmehr A, Ajam H. Turbulent mixed convection of a nanofluid in a horizontal curved tube using a two-phase approach. International Communications in Heat and Mass Transfer, 2010, 37(10): 1551-1558

[10] Kalteh M, Abbassi A, Saffar-Avval M, Harting J. Eulerian-Eulerian two-phase numerical simulation of nanofluid laminar forced convection in a microchannel. International Journal of Heat and Fluid Flow, 2011, 32(1): 107-116

[11] Akbari M, Galanis N, Behzadmehr A. Comparative analysis of single and two-phase models for CFD studies of nanofluid heat transfer. International Journal of Thermal Sciences, 2011, 50(8): 1343-1354

[12] Lotfi R, Saboohi Y, Rashidi A M. Numerical study of forced convective heat transfer of nanofluids: Comparison of different approaches. International Communications in Heat and Mass Transfer, 2010, 37(1): 74-78

[13] Huminic G, Huminic A. Numerical study on heat transfer characteristics of thermosyphon heat pipes using nanofluids. Journal of Energy Conversion and Management, 2013, 76: 393-399

[14] Tzeng S C, Jeng T M, Wang Y C. Experimental study of forced convection in asymmetrically heated sintered porous channels with/without periodic baffles. International Journal of Heat and Mass Transfer, 2006, 49(1-2): 78-88

[15] Kurtbas I. The effect of different inlet conditions of air in a rectangular channel on convection heat transfer: Turbulence flow. Experimental Thermal and Fluid Science, 2008, 33(1): 140-152

[16] Ko K H, Anand N K. Use of porous baffles to enhance heat transfer in a rectangular channel. International Journal of Heat and Mass Transfer, 2003, 46(22): 4191-4199

[17] Rashmi W, Ismail A F, Khalid M, Faridah Y. CFD studies on natural convection heat transfer of Al₂O₃-water nanofluids. Journal of Heat and Mass Transfer, 2011, 47(10): 1301-1310

[18] Fluent 6.3 Users Guide. Lebanon: Fluent Inc., 2006

[19] Jafari A, Tynjälä T, Mousavi S M, Sarkomaa P. Simulation of heat transfer in a ferrofluid using computational fluid dynamics technique. Journal of Heat and Fluid Flow, 2008, 29(4): 1197-1202

[20] Jafari A, Tynjälä T, Mousavi S M, Sarkomaa P. CFD simulation and evaluation of controllable parameters effect on thermomagnetic convection in ferrofluids using Taguchi technique. Journal of Computers and Fluids, 2008, 37(10): 1344-1353

[21] Schiller S, Naumann A. A Drag Coefficient Correlation. Berlin: Z Ver Deutsch Ing., 1935, 318-320

[22] Drew D A, Lahey R T. In Particulate Two-Phase Flow. Boston: Butterworth-Heinemann, 1993

[23] Ranz W E, Marshall W R. Evaporation from drops. Part I. Journal of Chemical Engineering Progress, 1952, 48: 141-146

[24] Wen D, Ding Y. Experimental investigation into convective heat transfer of nanofluids at the entrance region under laminar flow conditions. International Journal of Heat and Mass Transfer, 2004, 47(24): 5181-5188

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