CFD study on counterflow ceramic microchannel heat exchanger with different fins

The conventional heat exchangers cannot satisfy the high efficiency and power requirements due to the low heat transfer performance and large volume. With the development of microscale manufacture technology, the ceramic micro-channel heat exchangers are recommended to be used to the highly-efficiency power and propulsion systems, especially the very high temperature conditions. The present paper analyzes the thermal hydraulic performance of the alumina-based ceramic microchannel heat exchangers with four different fins (straight, Zshaped, airfoil and S-shaped). The numerical results show that the maximal heat transfer rate and heat transfer effectiveness of the heat exchanger with Z-shaped fins reach 90.7 W and 61%, respectively. The temperature distribution of both fluid sides and solid body is predicted. Moreover, the pressure drop and the ratio of E/k are used to evaluate the general heat exchanger performance. The ratio of E/k is smaller than unit of ten at the low Reynolds number and increases greatly at high Reynolds number.