马赫 2 凹腔燃烧室火焰振荡特性实验研究

In this study，the proper orthogonal decomposition(POD)and dynamic mode decomposition(DMD) methods are applied to the analysis of flame self-emission images，aiming to explore the combustion oscillation characteristics under typical operating conditions in a scramjet cavity combustor. For this purpose，the feasibility and effectiveness of the statistics-based methods for analyzing the flame oscillation are first verified based on a laboratory controlled forced excited flame. The methods are then applied to the investigations of the Mach-2 scramjet model combustor，with a specific focus on the flame oscillation features of a large length-to-depth ratio cavity. Compared with the previous results，this work demonstrates that the cavity structure with a large length-to-depth ratio can effectively suppress combustion oscillation.