The Numerical Research About The Impact That Airflow Enthalpy Produce Upon The Oxidation On The Surface Of Non-ablative Material

With the development of hypersonic vehicles, the ultra-high temperature thermal protection composite materials have been a new concern in recent years. As the purpose of this paper, a coupled calculation method of flow field and heat-conduction in solid materials is established, by which the numerical simulation involving external flow field, surface oxidation and internal heat-conduction of non-ablative material could be applied for different flow situations.This paper consists of five chapters. The first chapter is a introduction including background and significance of non-ablative material research, investigation approaches, current difficulties and the development at home and abroad. Finally, the main work of this paper is introduced briefly.The second chapter is the numerical method of flow field. This chapter presents the three-dimensional reactive flow governing equations, and discusses in detail the low velocity preconditioning method, finite volume approach, LU-SGS implicit iterative method, Jameson central difference scheme, S-W flux vector splitting scheme, boundary conditions and so on.The third chapter is the validation of the numerical method. Several cases including 2-D channel with a bump, NACA0012 airfoil, axisymmetric sphere and column are calculated to validate the simulating capabilities of the numerical method for inviscid, viscid, low enthalpy and high enthalpy flow in comparison with commercial software FLUENT, referenced literature or experimental data. The results show that the preconditioning method has high precision and good reliability.Method of coupling flow field and inner heat-conduction is introduced in the fourth chapter. Using Crank-Nicolson scheme, the 1-D heat-conduction equations are solved for interior temperature field, and the results are compared well with commercial software CFD-ACE. Based on the mass conversation, existing chemical model, boundary conditions of heat flux and temperature on material's surface, the flow filed, surface oxidation and heat-conduction are related.In the fifth chapter, the model is simulated for different flow enthalpy situations in order to calculate the parameters of flow field and the inner temperature distribution of solid materials. The effect of airflow enthalpy on the surface oxidation is analyzed. The last part is the conclusion, which summarizes this paper's work, and forecasts the work in the future.