Thermo-structural design of strut based flame holder for scramjet combustor

Abstract

Flame holders are critical for efficient combustion in scramjet engines. There are various flame holder concepts, among them strut is one of the most prominent ones. Strut based flame holders decelerate the supersonic flow, providing more time for fuel air mixing and combustion. Although, this exposes the strut to very high as well as spatially varying pressure and heat flux giving rise to high temperature and stress across its structure. Thus, its structural design becomes highly challenging and its thermo-structural behaviour needs to be investigated for a robust design. In this work, spatially varying pressure and heat flux have been estimated using computational fluid dynamics analysis, which are used as boundary conditions for subsequent thermo-structural analysis. Based on thermo-structural behavior of strut, a multi-layer material system consisting of ZrB2-SiC and phenolic cork has been proposed to mitigate high temperature and stress. This novel multi-layer material system, effectively reduces the temperature and stress experienced by the strut’s metallic interior to 910 K and 102 MPa respectively.