Calculation method for evaluating heat insulation performance of complex multi-layer thermal protection structure

Abstract

The invention relates to a calculation method for evaluating the heat insulation performance of a complex multi-layer thermal protection structure, and the method comprises the steps: determining the initial parameters of the multi-layer thermal protection structure, including the number of layers, the thickness of each layer, the thermophysical parameters of each layer, such as the density, the heat conductivity coefficient, the specific heat capacity, the equation of a heat absorption heat source, and the change relational expression of the air gap thickness and the thermophysical parameters; establishing a differential equation set of the multi-layer thermal protection structure, giving a thermal boundary condition and an interlayer continuity condition, dividing units based on a finite element method, discretizing the differential equation set, calculating a thermal capacity matrix, a thermal conductivity coefficient matrix and a thermal load matrix, and establishing a matrix equation set; and solving the matrix equation set by adopting a Gaussian-Seidel method to obtain node temperature and outer wall surface temperature distribution of the multi-layer thermal protection structure. The heat transfer calculation model of the multi-layer thermal protection structure can be established, and the method is suitable for evaluating the thermal insulation performance of the multi-layer thermal protection structure in different complex thermal environments.

Description

technical field [0001] The invention belongs to the field of engine auxiliary testing, and particularly relates to an infection calculation method of a multi-layer thermal protection structure of a combustion chamber. Background technique [0002] With the continuous improvement of the performance requirements of aero-engines, the gas temperature in the combustion chamber of the engine continues to rise, and the demand for high-efficiency thermal protection of the metal outer wall of the engine is also more urgent, especially in solid fuel ramjets, the thermal insulation effect of the thermal protection structure appear particularly important. The thermal protection of the engine combustion chamber can be divided into active thermal protection and passive thermal protection. Passive thermal protection is to use a thermal protection structure that is resistant to high temperature and ablation to effectively thermally protect the metal casing of the engine to prevent the metal...

AI Technical Summary

Problems solved by technology

Existing calculation methods generally use the finite difference method to calculate one-dimensional transient heat conduction. In some commercial software, additional heat sources that change with time can also be edited. However, the thermal physical parameters of materials that change with time or with temperature are considered. The influence of internal heat source over time, the influence of dynamically changing interlayer air gap, and the computational models that can quickly make accurate predictions are still relatively rare

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