Design and Analysis of Two Throat Wind Tunnel

Abstract

To aid in understanding the concepts of aerodynamics, wind tunnels are used. The aim of this paper is to design and analyze a two throat supersonic wind tunnel to give a better start-up condition at supersonic speeds. As the tunnel design involves high complexity, it is generally convenient to divide into segments. Initially, nozzle segment is developed using the method of characteristics (MOC) because, a careful designed nozzle is vital for tunnel function. In the next step, a settling chamber is introduced at the nozzle exit to straighten the flow, just before it enters the test section and the diffuser is designed to reduce the losses related to shocks attached. As we know that second throat at the diffuser section plays an important role in starting of a supersonic tunnel, so the area of the second throat is increased. In next phase, all segments are integrated and analyzed using the commercial code. Numerical analysis carried out reveals that the acceptable numerical accuracy is achieved with practice levels of grid resolution (300 x 30,) with the assumption that in absence of separation, low turbulence intensifies due to the effect of large acceleration along the downstream of the tunnel. The flow solutions give a better insight of understanding the flows, to investigate the effect of numerical code and grid independence. From this work, the necessity of grid dependence study and to the quantification of numerical error has been addressed by representing the computational results in complicated airways