Effects of isolator length on pseudo-shock wave in a rectangular duct.

The scramjet isolator length is a very important influence factor on the stability of scramjet engines. The effects of the isolator length on the pseudo-shock wave (PSW) were studied through a numerical method. The steady and unsteady PSW characteristics were analyzed to explore the influence mechanism of the isolator length. The numerical model was validated with the existing experimental results, and the validation results show that the numerical model has high accuracy. The effects of the structural variation of the PSW on self-excited oscillation were explored at different isolator lengths. Result shows that increasing the isolator length increases the length of the PSW. The leading shock becomes stable with the increasing of PSW length, and the following shocks become unstable. This phenomenon indicates that the unsteady characteristics of self-excited oscillation are closely related to the PSW structure. The influence mechanism of isolator length is represented by the amplitude difference of the leading and following shocks caused by the PSW structure variation. [ABSTRACT FROM AUTHOR]