Time-Accurate Simulation of Shock Propagation and Reflection in an Axi-Symmetric Shock Tube

Abstract

An axi-symmetric shock-tube model has been developed to simulate shock propagation and reflection in both inviscid and viscous nonreactive flows. Simulations were performed for the full shock-tube geometry of the high-pressure shock tube facility at Texas A&M University. The CFD code FLUENT was employed to simulate the shock propagation and reflection processes in the shock tube, and the flow properties behind the reflected shock wave were obtained by solving the axi-symmetric, unsteady Euler and Navier-Stokes equations. Computations were carried out based on the finite volume approach and the AUSM+ flux differencing scheme. Adaptive mesh refinement (AMR) algorithm was applied to the time-dependent flow fields to accurately capture and resolve the shock and contact discontinuities as well as the very fine scales associated with the viscous effects. The bifurcation phenomenon resulting from the interaction of the reflected shock wave and the boundary layer has been accurately simulated. Conjugate heat transfer modeling was made possible in conjunction with the viscous model which enhanced the credibility of the results. The robustness of the numerical model and the accuracy of the simulations were assessed through validations with the analytical ideal theory and experimental measurements. The model is shown to be capable of accurately simulating the shock and expansion wave propagations and reflections as well as the flow non-uniformities behind the reflected shock wave associated with the viscous non-ideal effects.