Zhongqi Wang

Mechanism Study on Local Unstart of Hypersonic Inlet at High Mach Number

A viscous numerical simulation was performed to study the forebody shock reflection at the cowl under the condition of inflow Mach number higher than the design value for different forebody/cowl configurations. With the help of shock reflection theory and numerical simulation, it was found that the shock reflection changed from overall regular reflection wave configuration to overall Mach reflection wave configuration as the cowl angle decreased or the ramp angle increased. Mach reflection in this situation would be harmful; it could result in the shock propagating forward to cause a shock detachment at the cowl lip (the so-called local unstart of inlet in this paper). And the local unstart of inlet essentially resulted from the transition of forebody shock reflection from overall regular reflection to overall Mach reflection at the cowl. It was also found through comparison with inviscid analysis that the viscous effect had to be considered in the local unstart of inlet for practical applications. The ob...

New Method for Solving One-Dimensional Transonic Reacting Flows of a Scramjet Combustor

A new solution method is proposed to solve the one-dimensional transonic reacting flows of a scramjet combustor, which represents a mathematical singularity in the governing equations when the flow velocity approaches the speed of sound. The governing equations of the one-dimensional transonic flows are rewritten by using a variable transformation method and, in this way, the singularity of the governing equations is eliminated. Subsequently, a forward iterative shooting method is introduced to deal with the numerical problem appearing in the flow that includes finite-rate chemistry and high-temperature gas properties. Comparative analysis is performed to evaluate the method presented in this paper and previous methods. The results show that it has a wider applicability and better stability in solving the one-dimensional transonic reacting flows than previous methods. One major advantage of this method is that, as a result of the elimination of the singularity using variable transformation and the introdu...

Predictor–Corrector Method for Scramjet Inlet Air Mass Flow Rate Measurement

The accurate and real-time measurement of the scramjet inlet air mass flow rate is critical to flight control. To measure the scramjet inlet air mass flow rate, air data parameters are estimated. T...