Numerical investigation of a microchannel heat exchanger with different cross sections in transition flow regime

There are various geometries that can be used in making a microchannel heat exchanger (MCHE). Such geometries have remarkable consequences on the thermal and hydrodynamic performance of the MCHE. In this paper, the effects of channel size and geometry on the performance of a counter flow microchannel heat exchangers (CFMCHE) are investigated numerically. The flow regime is considered 3D developing flow in transitional regime. Various channels with different cross sectional shape are investigated for the same overall volume of the MCHE in transitional flow regimes. Typical results are also compared with available studies for specific geometries in the laminar flow regime. Using validated numerical simulation, MCHE heat transfer performance and pressure drop for each geometry is determined and discussed. Results show that increasing the number of channels results in increasing both the effectiveness and the pressure drop. Comparison of the results also illustrate that the microchannel with circular cross section seems to have the best overall thermal and hydraulic performance among the studied geometries

کلیدواژه ها:

Microchannels ، Heat exchanger ، Transitional regimes ، Conjugate heat transfer