Experimental study and performance analysis of high-performance micro-channel heat exchanger for hypersonic precooled aero-engine

The microchannel heat exchanger is a critical component of hypersonic precooled aero-engines, facing huge challenges from design and manufacture due to the demanding requirements of higher power-weight ratio and lower pressure loss. In this paper, a segmental method (SEG) taking the influence of fin efficiency into consideration is proposed to analyze and evaluate the performance of microchannel heat exchanger for precooled engines. In order to validate the method and investigate the flow and heat transfer characteristic, a microchannel heat exchanger with the hydraulic diameter of 263.6 mu m was fabricated and measured on a 3 kW open loop experimental platform. The experimental results indicate that the maximum deviation between the heat transfer rate predicted by the SEG method and the experimental data does not exceed 5% on the condition of balanced flow and unbalanced flow. Furthermore, a new correlation for pressure drops based on experimental results without heat transfer is developed to correct the results predicted by the SEG method and the maximum deviation does not exceed 3%. At last, the influence of the geometric parameter of the basic heat transfer unit was thoroughly discussed for further understand the performance of microchannel heat exchanger under typical working conditions. It is indicated that potential channel width should not be more than 0.5 mm (d(h) =0.305 mm) in the case of integrating various factors.