A Numerical Study of Vorticity-Enhanced Heat Transfer

Dissertation Defense
Tuesday, June 24, 2014 - 2:05pm for 1 hour (actually 50 minutes)
Skiles 005
Xiaolin Wang – School of Mathematics, Georgia Tech
Xiaolin Wang
In this work, we numerically studied the effect of the vorticity on the enhancement of heat transfer in a channel flow. Based on the model we proposed, we find that the flow exhibits different properties depending on the value of four dimensionless parameters. In particularly, we can classify the flows into two types, active and passive vibration, based on the sign of the incoming vortices. The temperature profiles according to the flow just described also show different characteristics corresponding to the active and passive vibration cases. In active vibration cases, we find that the heat transfer performance is directly related to the strength of the incoming vortices and the speed of the background flow. In passive vibration cases, the corresponding heat transfer process is complicated and varies dramatically as the flow changes its properties. Compared to the fluid parameters, we also find that the thermal parameters have much less effect on the heat transfer enhancement. Finally, we propose a more realistic optimization problem which is to minimize the maximum temperature of the solids with a given input energy. We find that the best heat transfer performance is obtained in the active vibration case with zero background flow.