An investigation on aerodynamic and thermodynamic characteristics of a precooled intake for the supersonic precooled turbine engine

Precooling is a promising approach to expand the flight envelope of conventional turbine engines. The precooled intake which is a critical compression component restricts the performance of the precooled turbine engine. In contrast to previous studies that precooler and intake were researched separately, this study integrates them into a precooled intake system and adopts a refined simulation method to efficiently and accurately investigate its aerodynamic and thermodynamic characteristics. The axisymmetric supersonic intake calculation is simplified to a two-dimensional flow domain. An isotropic porous media model and source term method are selected to simulate pressure drop and heat transfer of the precooler. The performance of precooled intake is investigated under different Mach numbers, compressor channel mass flow rate, tube transverse pitch and number of tube rows. It is found that under cruise condition (Ma₀ = 4), when the air of the intake outlet is cooled from 919.17 K to 499.69 K, the total pressure recovery coefficient at the precooled intake outlet increases from 0.493 to 0.518, while the total pressure distortion decreases by more than half. At Ma₀ = 2 and Ma₀ = 3, the augment in the bypass channel pressure improves the mass flow rate and total pressure recovery coefficient of the compressor channel. Additionally, as the tube transverse pitch increases and the tube rows decrease, the heat exchange area and cooling efficiency of the precooler decline. The drop in the precooler resistance enhances the non-uniform of mass flux and raises total pressure distortion. The results indicate that the coupled numerical method effectively simulates the precooled intake characteristics, and balancing heat transfer and flow resistance is essential.