INTERACTION OF SUPERSONIC EXPANSION FLOW WITH BOUNDARY-LAYER IN UNSYMMETRICAL DUCT

Study of unsymmetrical supersonic flow is important not only for basic research in gas dynamics but also for applications such as to jet pro pulsion and analyses of turbomachines. In the present study, a shock t ube was used to generate supersonic flows in an unsymmetrical duct. Th e generation and oscillation of a pseudo-shock wave due to the interac tion of a supersonic expanding flow with a boundary layer developed on the duct wall were studied experimentally using pressure transducers, and also by taking schlieren or schlieren interferometric photographs . The observed pseudo-shock wave oscillated in the flow direction. Its oscillation frequency was determined from schlieren photographs and c ompared with that obtained from pressure measurements. In addition, th e Navier-Stokes equations were solved numerically to obtain steady-sta te solutions of the corresponding flow field.