The Design And Experimental Study Of A "Supersonic-supersonic" Mixing Layer Wind Tunnel

The study of "supersonic-supersonic" mixing layer is one of the advanced domains in aerodynamics. Being the foundation of experiment study of "supersonic-supersonic" mixing layer, wind tunnels which can realize good flow performance are required.In order to meet the requirement of the experimental studies of mixing layer, the paper has designed the new "supersonic-supersonic" mixing layer wind tunnel. When deep analyzing and improving designing the mixing layer wind tunnels, the paper has referred to the basic designing idea of general supersonic wind tunnel, at the meantime, the actual requirement of testing the flow of mixing layer has been considered as well. At first, the paper analyzed the parameters which is necessary to construct "supersonic-supersonic" mixing layer flow, then contra-posing these parameters, holistic design in function mode and structure of the wind tunnels has been done, at last, every part of the wind tunnels has been designed. The newly designed "supersonic-supersonic" wind tunnels basically fulfilled the requirement of present experimental study of the mixing layer. They are of small size, simply structure, and can be conveniently handled as well, all of which make them serve the experimental study of mixing layer well.To make sure the newly designed wind tunnels have good performance, the paper has installed and tested them. Judging from the result of the test experiment, they can realize perfect "supersonic-supersonic" mixing layer flow structure, by changing the jet section, mixing layer flow of three convective mach numbers can be obtained as well. At the other hand, because of the errors brought in the process of machining and installation, the actual flow of the wind tunnels would differ from the assumed state. So at first, the paper has calibrated the convective mach numbers of three newly designed wind tunnels by electronic pressure scanner. Then to obtain the basic character of the mixing layer flow structure, various flow visualization measure such as schlieren, Nano-particle based Planar Laser Scattering and Background Oriented Schlieren are utilized. After these test experiment, the paper has obtained experimental results of different temporal and spatial resolution. By comparing and analyzing these results, the paper has gotten the basic feature and character of the "supersonic-supersonic" mixing layer of different convective mach numbers, which supplied experimental warranty for improving the mixing layer experimental study.In conclusion, the jobs of designing and testing the new "supersonic-supersonic" mixing layer wind tunnels which the paper has finished, have referred to two basic problem in the experiment study of mixing layer, namely the wind tunnel equipment and the testing measure. These jobs also laid firm foundation of the embedded study of "supersonic-supersonic" mixing layer.