超燃冲压发动机非定常流场的动态模态分解

Dynamic Mode Decomposition of the Unsteady Flowfield in a Scramjet

本文采用一种新兴的数据分解和重构技术——动态模态分解(DMD)方法,对超燃冲压发动机过渡式凹槽非定常流动的纹影和火焰自发光图进行模态分解和重构。对于过渡式凹槽冷流流场,采用少量能量较高的模态即可重构出主要流动结构的动态变化。对于氢气燃烧流场,采用多达模态总个数的1/6的模态重构出的图像与原始图像仍然相差甚远。

A novel data decomposition and reconstruction technique,namely Dynamic Mode Decomposition(DMD),is used to analyze the flow structures in the schlieren and the flame emission photos of the transitional-type cavity flows.The photos of the transitional-type cavity flows without combustion can be reconstructed with a small quantity of high energy modes,and the reconstructed photos can capture the dominant unsteady characteristics of the flow structures.In contrast,the reconstructed photos of hydrogen combusting flows are deviated from the original photos,even when the reconstructed photos are reconstructed with 1/6 of the total modes.