Structure effect on thermal-hydraulic performance in liquid metal – Aviation kerosene printed circuit heat exchanger

A liquid metal to kerosene printed circuit heat exchanger (PCHE) is initially presented in this study to address the heat transfer efficiency and compactness difficulties of traditional heat exchangers aboard aircraft with increasing heat flux. The structure of PCHE must be particularly constructed because of the extremely high heat conductivity and low Prandtl of liquid metal. As a result, for the structural design and optimization of PCHE in this study, three-dimensional numerical simulation method is used, and an experimental platform for Ga-In-Sn alloy and aviation kerosene using a spiral heat exchanger is built to verify the precision of simulation results. The optimal characteristics of a PCHE microchannel based on Ga-In-Sn alloy are established, according to simulation results: a trapezoidal cross-section, 0° of inclination, and a single hot side-double cold side structure. The flow and heat transfer characteristics in the axial direction of the TT2 microchannel demonstrate that temperature has the minimal effect on the convective heat transfer of Ga-In-Sn alloy under low Re conditions. However, temperature improves the convective heat transfer of Ga-In-Sn alloy in high Re working circumstances, suggesting that Ga-In-Sn alloy is better suited to cooling situations with high heat flux and hypersonic aircraft cooling.