Numerical investigation of conjugated heat transfer mechanisms of supercritical hydrogen-helium in PCHE channels

In this study, straight and z-shaped channel PCHEs are employed as hydrogen-helium heat exchangers in Synergistic Air-breathing Rocket Engine (SABER). Conjugated heat transfer mechanisms and characteristics of supercritical hydrogen-helium are studied numerically. The results of the straight channel indicate that when the mass flow rate of the cold (H₂)/hot (He) side is 38/280 kg/(m²·s), a greater comprehensive performance of flow and heat transfer can be obtained. The influence of gravity on the hot side is significantly less than that on the cold side. The increase in plate thickness enhances heat transfer, while the effect of rib thickness is the opposite. As the bend angle decreases, the heat transfer coefficient of the z-shaped channel becomes higher. The heat transfer characteristics of the cold side vary more significantly with the bend angle than that of the hot side.