双模态超燃冲压发动机准一维流耦合方法与验证 *

In order to improve analyzed precision and long period of calculation problem for dual mode scramjet, a coupling method for internal flow analysis is presented based on the quasi one dimensional flow. Such method can be used in the coupling analysis of isolator and combustor of dual mode scramjet. It solves the back pressure matching problems of the isolator and the combustor which is caused by thermal choking in ramjet mode. The flow matching analysis of isolator and combustor is completed, and the flow performance along the channel of dual mode scramjet and rocket based combined cycle (RBCC) engine in ramjet and scramjet mode is obtained. The results show that, (1) Comparing to direct connection test of dual mode scramjet mode, the predicted error of separated point of the flow in isolator is between 1.4% and 11.2%, and the predicted error of the maximum pressure is between 15.6% and 21.6%, but the average error of the pressure along the channel is less than 9.6% in ramjet mode. In scramjet mode, the predicted error of the maximum pressure is less than 3.75%, and the error of the location of the maximum pressure is less than 2%. (2) Comparing to integral free jet test of RBCC engine, the predicted error of flow's separated point in isolator is less than 2.1%, the average error of the pressure along the engine's channel is less than 10.5%. The comparison shows that the quasi 1-D method in this paper has certain credibility for dual mode scramjet.