Abstract
Heat transfer performance of two-stream parallel and counter-flow gas-to-gas micro-heat exchangers are investigated numerically. Flow passages are plane channels with heights in the range of and selected lengths of and . Numerical methodology is based on the arbitrary-Lagrangian-Eulerian method. Computations were performed to find the effects of capacity ratio, channel height, and length on the heat transfer characteristics of micro-heat exchangers. To results are presented in the form of temperature contours, bulk temperatures, total temperatures, and heat flux variation along the channel. It was found that the temperature inversion occurs under certain conditions. Also, the effectiveness and the number of transfer units approach and the estimation of the heat exchange rate were discussed. The range of parameters where the predicted effectiveness agrees with the numerical result were investigated.