Evolution Mechanism of Aero-optical Effects in Supersonic Shear Layers

摘要

The vortices inside shear layers impose remarkable aero-optical distortions on a beam even at moderate subsonic speeds. However, knowledge about aero-optical effects caused by vortices in the flow field, especially their spatiotemporal evolution, is limited for supersonic shear layers because the flows have extremely high speeds. In this study, the spatiotemporal evolution of aero-optical effects caused by vortices in the supersonic shear layer was investigated. A large eddy simulation was used to simulate the supersonic flow. The instantaneous and time-averaged optical path difference of the shear layer flow acted as two evaluation parameters to quantitatively investigate the evolution characteristics of aero-optical effects in supersonic shear layers. Two suits of cases were considered, that is, the compressibility of flow field and initially normal disturbance making up the supersonic shear layer. These cases were performed to investigate in detail the evolution characteristics of vortices in the supersonic shear layer.