Numerical investigation of the effect of injector installation on the performance of blowdown supersonic wind tunnels

Mehrdad Bazzaz Zadeh, Mojtaba Dehghan Manshadi, Mehdi Jahangiri
Embedding the injector in the in the wind tunnel provides the opportunity to launch the wind tunnel at lower compression ratios. Since the duration of the experimental data collection is limited in blowdown supersonic wind tunnel, proper design and exploitation of the injector in a way to allow tunnel launching at decreased compression ratios, provides significant influence on the saving the compressed air of the storage tank and increasing the the experiment duration. It has been attempted in
more » ... been attempted in this work to study the effect of installation of the injector in a blowdown type supersonic wind tunnel with a mach number of 3 through assessing the boundary layer and the flow physics inside the wind tunnel. The result show that the injected flow increases the energy level of the low energy boundary layer, so as the energy of the boundary layer in a placed ahead of the injector location is higher than a place before the injector location. This fact results in a decreased required compression ratio for tunnel launching. The physics of the formed flow was studied and physical phenomena such as boundary layer separations, bow shock, barrel shock and mach disk were reported around the injection site.