Large eddy simulation of shock vector control using bypass flow passage

A detail description of the unsteady phenomena of three-dimensional shock vector control (SVC), including recirculation zones and shear layer regions, has been presented in this study. Shock vector control is a really efficient way to achieve flight direction control of high speed vehicle. Large eddy simulation (LES) has been applied to capture the unsteady characteristics of SVC method using bypass flow passage. Comparison of RANS and LES has been conducted in this study. LES model shows better results than others and it is able to capture the unsteady process very well. In this study, the separation bubble upstream of the injection port is the main source of flow unsteadiness. Large scale eddies in the whole flow field have been resolved by the LES model. Unsteady characteristics of SVC method at different nozzle pressure ratios (NPR) have been investigated. The time histories of thrust vector angle at different NPRs have been recorded by the LES model. The results indicate that it is possible to achieve SVC with the range of bypass mass flow ratio less than 7%. It is also revealed that nozzle pressure ratio has a strong effect on the unsteady phenomenon of SVC system.