Numerical and correlation analysis of conjugate heat transfer over the discrete braided composites plate

Braided composites, which have excellent mechanical and thermophysical performance, have been considered promising materials widely used in aerospace, renewable energy, and other fields. However, the conjugate heat transfer mechanism between working fluids and braided structures is still unclear. Due to the complicated structure and computational limitation, with a neglection of the structural discrete feature and velocity distortion, current pertinent research primarily relies on the equivalent method of homogenization. In this research, a detailed numerical investigation of conjugate heat transfer over a three-dimensional four-directional (3D4d) braided composite plate with anisotropic and discrete features is presented. The full-size geometric structure of the 3D4d braided plate is first established utilizing the representative volume element (RVE). For such periodic structures, a continuous Eulerian grid generation technique is developed. A local coordinate system approach for the heat conduction spindle based on discretization is subsequently proposed to address the anisotropy of heterogeneous materials. The accuracy of the proposed discrete model processing approaches is verified by comparison with homogenization techniques widely used and experimental data in the literature. It is discovered that the discrete structure with an interfacial thermal dispersion, has a unique physical field distribution in comparison to the homogenization cases. Moreover, a semi-theoretical heat transfer criterion for 3D4d composite is established based on the thermal correction of dispersed interface.