A simplified numerical method based on anisotropic porous media model for the precooler of the hypersonic precooled engine

The precooler is a key component of hypersonic precooled engine, and its actual structural have a high anisotropy in the axial, circumferential, and radial direction. Considering the non-uniform flow inside the precooler is crucial to study the flow and heat transfer characteristics of the precooler. The previous simplified method for the precooler has not fully considered the flow non-uniformity of the axial, radial and circumferential direction. In this paper, a simplified numerical method based on anisotropic porous media model for the precooler was proposed. The unique aspect of this method is the integration of anisotropic surface porosity of porous media model with the zero-dimensional heat transfer model. In addition, the influence of key structural parameters on the flow and heat transfer characteristics of precooler was studied. It is found that as the tube transverse pitch increases from 2 to 3.5, the total flow rate increases by 11%, and the heat exchange rate decreases by 25%. As the number of tube rows increases from 7 to 13, the heat exchange rate increases by 22%, but the total pressure loss coefficient increases from 0.046 to 0.082. In addition, the decrease of inner diameter of the precooler improves the heat exchange rate, but reduces the flow capacity of the precooler. These results indicate that the simplified numerical method is capable of simulating the behavior of precooler and provides some guidance on the design of precooler.