Transient numerical investigation on coupled heat transfer of regenerative cooling channels with typical lattice sandwich structures

To meet the growing requirements of thermal protection for scramjet engines, two typical lattice structures, Kagome and pyramid, are applied to the regenerative cooling channel. This paper presents a transient numerical investigation of coupled heat transfer for lattice sandwich cooling channels. The results indicate that under identical pressure drop, heat flux, and coolant flow conditions, compared to the traditional rectangular channel, the maximum temperatures of the back side wall for the two lattice channels decrease by 40.6 % and 39.2 %, respectively, with a faster temperature response rate. However, the maximum temperatures of gas side wall for the two lattice channels are 9.2 % and 10.2 % higher than that for the rectangular channel, potentially increasing the risk of overtemperature damage. Notably, under the same conditions of relative density for cooling channels and contact area between the lattice core and the bottom panel, the heat transfer calculation results for Kagome lattice channel and pyramid lattice channel are almost similar.