Abstract
In this Letter, we have quantified the zones of turbulence in transonic shock diffraction across a 90° step corner using Lamb vector analysis. We have analyzed the nature of the three-dimensional turbulence structures using invariants of the velocity gradient tensor. From our results, we conclude that the vortex-induced shock, the lambda shock on the shear layer, and the Kelvin–Helmholtz instability forming on the shear layer are the main contributors in turbulence generation. In our study, we have shown that two-dimensional simulations can resolve the gasdynamic behavior accurately, though three-dimensional simulations are required to understand turbulent structures.