Critical area method for mass flow matching of dual-mode scramjet

The lumped parameter model for thermo-throat (Ma=1.0) simulation was established based on 0-D conservation equations(continuity equation,momentum conservation equation and energy conservation equation) of the control volume,including:wall friction model,fuel injection model,fuel atomization and mixing model,and chemical kinetics model.To solve the problems in simulating the thermo-throat with lumped parameter model,a critical area method based on mass flow balance was proposed to simulate the 1-D flow field of the combustor.With this method,the mass flow balance between isolator and combustor in different modes when a dual-mode scramjet worked in thermo-throat condition was achieved,and the thermo-throat was accurately captured;in addition,the isolator flow state,the combustor operation modes and the flow path parameters were determined.The results show that the lumped parameter computation model with the critical area method can solve the problems in thermo-throat simulation,its computing accuracy reaches 10^-4,and the computing time at every working condition is less than 0.1s.