SCRAMJET CHARACTERISTICS AT HYPERVELOCITY CONDITION OVER MACH 10 FLIGHT - APPLICATION OF A DIVERGING COMBUSTOR

摘要

A new scramjet engine model was developed and tested in the high enthalpy shock tunnel HIEST at the hypervelocity condition corresponding to the flight Mach number over 9. In the design of the new engine, the pressure at the combustor entrance was set to be twice higher than that of the previous engine and the combustor length was reduced while remaining the gas temperature at the combustor entrance adequately low. The results showed that the combustor performance at the stagnation enthalpy condition of 7MJ/kg or higher was remarkably improved with the present engine. The results positively supported that the high pressure at the combustor entrance and the reduced combustor length was advantageous to achieve high combustor performance at the hypervelocity condition. An attempt was made to apply a combustor with a diverging section to the present engine with an aim of further reduction of the net heat release loss by gradually expanding the combusting gas flow. However, no significant improvement in the combustor performance was observed in the present application.