NUMERICAL SIMULATION OF GEOMETRICAL EFFECTS ON THE LIQUID FLOW AND HEAT TRANSFER IN SMOOTH RECTANGULAR MICROCHANNELS

摘要

The flow and heat transfer characteristics of water in smooth rectangular microchannels had been simulated numerically by using CFD method. Computational results showed that the ratio of the channel length and hydraulic diameter, hydraulic diameter, the ratio of height and width of microchannels, porous ratio had different effects on the flow and heat transfer of microchannels. On the condition of the ratio of the length and hydraulic diameter of channel greater than 70, thereby the entrance effects could be neglected, the effect of hydraulic diameter, the ratio of height and width of microchannels and porous ratio on flow and heat transfer in microchannels had been simulated respectively. The mechanism of flow and heat transfer of each condition had been obtained, which could offer important data to discuss the mechanism of flow and heat transfer in microchannels further and realize the goal of optimizing design of microchannel heat exchanger.