Abstract: A investigation on the interactions among thereflected-shock, boundary layer and contact region in the detonation-drivenshock tunnel was carried out by applying Navier-Stokes equations in amulticomponent system and the dispersion controlled dissipative (DCD)scheme. In addition, the physical mechanism of test gas contamination causedby the wall jet was analyzed, which dramatically reduces the experimentalduration in a shock tunnel. The numerical results indicated a simple andeffective method of installing to increase the experimental duration.