Study of transonic shock wave/boundary layer interactions subject to unsteady forcing

Understanding the unsteady behavior of shock waves is important for the design of high speed aeronautical applications. In this paper, we examine flow features that in fluence the unsteady behavior of a normal shock wave in a duct using analytical, computational and experimental tools. Results from experiments in a new Mach 2 wind tunnel facility at Imperial College London are presented and discussed, together with predictions from analytical and computational models. Comparison and validation of these results with previous studies is also performed. It is shown that 1D models capture important aspects of unsteady shock dynamics, including the characteristic behavior of a shock as a lowpass filter and previously unreported resonance effects. Results from a 2D ray-tracing model successfully capture the impact of flow non-uniformity due to viscous effects on the upstream propagation of pressure waves from a downstream source. It is postulated that this effect may be the cause of resonant behavior reported in previous studies. Work is ongoing to compare model predictions with results from experiments at Imperial College London.