Critical starting characteristics of hypersonic inlets

An airbreathing hypersonic vehicle model was tested in the Ma=7 wind tunnel.The experimental investigations yielded schlieren pictures of the inlet flow,static surface pressure measurements along inlet/internal flowpath and aerodynamic force distributions.The flow field characteristics were achieved,such as: unstarting hypersonic inlet,critical starting and starting condition.The ability of isentropic limit,Kantrowitz limit and Van Wie limit to predict the starting contraction ratio was assessed,showing that the isentropic limit and Van Wie limit could not estimate the allowable starting and maximum contraction ratio.The Kantrowitz limit is slightly conservative.The above results are helpful to the design of the hypersonic inlet and the assessment of starting performance.