The Design And Experimental Studies Of Supersonic Straight Through Wind Tunnel And "Supersonic-supersonic" Mixing Layer Wind Tunnel

The studies of supersonic turbulent mixing layer and the aero-optical effect of supersonic flow field are both the front domain of aerodynamics, in which the wind tunnel experiment is an very important method. The existing wind tunnels can not meet the requirement of experimental studies with the development of studies and improvement of experimental technique. In order to satisfied the new requirement of experimental study, in this paper, a supersonic straight through wind tunnel is designed to study the aero-optical effect of supersonic flow field and a "supersonic-supersonic" mixing layer wind tunnel is designed to study the turbulent structure of supersonic mixing layer.The supersonic straight through wind tunnel is driven by atmosphere and vacuum tank, of which the test section is 120mm×100mm and the design Mach number is 3 and 3.8 supplied by different nozzle contour. The four walls of the test section are composed of optical glass, which can meet the requirement of different optical flow visualization methods to reproduce the flow structure.The "supersonic-supersonic" mixing layer wind tunnel is also driven by atmosphere and vacuum tank, of which the test section is 100mm×50mm and the design convective Mach number is 0.3 and 0.6 by different combination of nozzles. The total pressure of low speed stream can be adjusted to realized pressure matched between two streams.The installation and calibration of the wind tunnels are accomplished in aerodynamics laboratory of National University of Defense Technology and the distribution of total pressure acquired by electronic pressure scanner is satisfactory. In order to investigate the inner flow structure of them, various flow visualization methods such as schlieren, Nano-particle based Planar Laser Scattering (NPLS) and Background Oriented Schlieren (BOS) are applied to realize multi-resolution visualization of the wind tunnel flow field, which are useful in studying aero-optical effect of supersonic flow and turbulent flow structure of supersonic mixing layer.