Numerical Study of Flow and Heat Transfer in a Wavy Channel
Vipin B. Gawande1, Abhishek G. Ramgadia2,a and Arun K. Saha2,b
1Department of Mechanical Engineering, National Institute of Technology, Nagpur, Maharashtra 440 010, India.
vipingawande@gmail.com
2Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016, India.
aabhiramg@iitk.ac.in
baksaha@iitk.ac.in
ABSTRACT
A two dimensional numerical study of fully developed flow and heat transfer through a horizontal wavy surface is presented. Time dependent Navier-stokes and energy equation have been solved using finite volume method. Four different geometries obtained by changing height ratios are studied. Attempts have been made to see the effect of streamwise domain length which is the integer multiple of periodic geometric domain length on the instantaneous flow and heat transfer characteristics. The flow and heat transfer characteristics do not show any dependence on length of the periodic domain which shows that geometric and flow periodicity are same. The effect of Reynolds numbers (25–600) and the height ratio on the flow field and heat transfer has been presented. The flow in the channels has been observed to be steady up to a critical Reynolds number which depends on the geometric configuration. Beyond the critical Reynolds number a self sustained oscillatory flow has been observed. As a result of this oscillations, there is increased mixing between core and near- wall fluids, thereby increasing the heat transfer rate. The effect of surface waviness on flow separation, pressure drop and heat transfer is presented.
Keywords: Wavy channel, Heat transfer, Fluid flow, Oscillatory flow.
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