Nonlinear pyrolysis layer model for thermal behavior of nonhomogeneous charring materials

Abstract

To improve the performance of charring materials as the thermal protection system in supersonic vehicles subjected to aerodynamic heating, we develop a nonlinear pyrolysis layer model of nonhomogeneous charring composites, propose a scheme of variable density in which the resin distribution of charring materials is taken as a piecewise linear function, and then simulate the thermal behavior of the design by means of the written calculation codes. This model reveals that the thermal behavior of charring materials depends not only upon several key parameters such as heat flux, moving interfaces, moving boundary and temperature-dependent thermal properties, but also upon variable density. Further numerical investigations point out that the pyrolysis layer plays a very important role in the thermal protection performance. This study will be useful for the optimization of the thermal protection system in supersonic vehicles.