Flow and heat transfer characteristics of intake-precooler system for hypersonic precooled aero-engine

•Coupled simulation and analysis of hypersonic inlet system were performed using CFD.•Working pressure ratio affected intake working condition and precooler performance.•Results illustrate the necessity of coupling the intake and precooler design. Precooled aero-engines are promising hypersonic propulsion mechanisms for hypersonic aircraft that are capable of taking off and landing horizontally. The performance of the intake-precooler system has a significant impact on the performance of the engine. In this study, a coupled simulation of a hypersonic intake with a precooler was performed using computational fluid dynamics. The pressure drop and heat transfer through the precooler are evaluated using porous media and dual cell heat exchanger models, respectively, without modeling the detailed structure of the heat exchanger. Coupled axisymmetric variable-geometry hypersonic intake-precooler simulations were conducted at typical operating conditions (i.e., at Mach numbers = 5.0, 3.5, and 2.0). The coupled flow and heat transfer characteristics and the effects of the working pressure ratio on the intake-precooler system were analyzed. It was found that the total temperature distortion of the airflow through the precooler at the cruising velocity (Ma = 5.0) reached 0.337. Besides, the loss of the airflow through the precooler at lower velocity (Ma = 2.0) accounted for 48.4% of the overall total pressure loss. These results indicate that the coupled simulation method is capable of simulating the behavior of hypersonic intake-precooler systems and provides some guidance on the design of precooled engines.