Numerical simulation of aerodynamic heating and stresses of chemical vapor deposition ZnS for hypersonic vehicles

Abstract

Abstract:Hypersonic vehicles subjected to strong aerodynamic forces and serious aerodynamic heating require more stringent design for an infrared window. In this paper, a finite element analysis is used to present the distributions of thermal and stress fields in the infrared window for hypersonic vehicles based on flowfield studies. A theoretical guidance is provided to evaluate the influence of aerodynamic heating and forces on infrared window materials. The aerodynamic heat flux from Mach 3 to Mach 6 flight at an altitude of 15 km in a standard atmosphere is obtained through flowfield analysis. The thermal and stress responses are then investigated under constant heat transfer coefficient boundary conditions for different Mach numbers. The numerical results show that the maximum stress is higher than the material strength at Mach 6, which means a failure of the material may occur. The maximum stress and temperatures are lower than the material strength and melting point under other conditions, so the material is safe.

Measurement method for high-temperature infrared optical constants of ZnS crystal materials in a multi-layer structure

“…Zinc sulfide (ZnS) crystal material [45][46][47], which has the advantages of high mechanical strength, high hardness, erosion resistant, and excellent optical transmission from the visible to infrared wavelengths, is the investigated semi-transparent material in this paper. ZnS was widely used as the infrared-transmitting window materials for optical systems so that the high-temperature optical properties of ZnS materials in the harsh thermal conditions are necessary to evaluate the high-temperature structure-stress and optical characteristics in applications.…”