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.
. [J]. Frontiers of Chemical Science and Engineering, 2014, 8(3): 320-329.
Ali SHAHMOHAMMADI,Arezou JAFARI. Application of different CFD multiphase models to investigate effects of baffles and nanoparticles on heat transfer enhancement. Front. Chem. Sci. Eng., 2014, 8(3): 320-329.
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
Tynj?l? 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 nano?uid 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 ?ow of nano?uids 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 nano?uid 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 nano?uid 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 nano?uid heat transfer. International Journal of Thermal Sciences, 2011, 50(8): 1343-1354
12
Lot? R, Saboohi Y, Rashidi A M. Numerical study of forced convective heat transfer of nano?uids: 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 nano?uids. 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 ?ow. 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 nano?uids. Journal of Heat and Mass Transfer, 2011, 47(10): 1301-1310
Jafari A, Tynj?l? T, Mousavi S M, Sarkomaa P. Simulation of heat transfer in a ferro?uid using computational ?uid dynamics technique. Journal of Heat and Fluid Flow, 2008, 29(4): 1197-1202
20
Jafari A, Tynj?l? T, Mousavi S M, Sarkomaa P. CFD simulation and evaluation of controllable parameters e?ect on thermomagnetic convection in ferro?uids using Taguchi technique. Journal of Computers and Fluids, 2008, 37(10): 1344-1353
21
Schiller S, Naumann A. A Drag Coef?cient 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 nano?uids at the entrance region under laminar ?ow conditions. International Journal of Heat and Mass Transfer, 2004, 47(24): 5181-5188
