CFD Modeling of Flow and Heat Transfer of Supercritical Helium in Capillary Tube

Abstract

A tube-intensive heat exchanger is intended to be used as precooler in strongly precooled aircraft engine. In the heat exchanger, supercritical helium is used as the cooling medium. In the present study, the flow of supercritical helium in the capillary tube in the case of high heat flux was modeled. The simulation results show that the physical property of the supercritical helium flow in the capillary tube are significantly changed; the pressure drop of the supercritical helium flow in the capillary tube is considerable and it is favorable to reduce the pressure drop by increasing the pressure of the fluid; the benefit of heat transfer enhancement incurred by the inside diameter reduction under low heat flux is lower than the cost of the pressure drop; but the benefit of the heat transfer enhancement incurred by the inside diameter reduction under high heat flux is higher than the cost of the pressure drop. The study serves as a basic reference for research on strong precooling technology.