Effect of Combustor Configuration on Flow and Combustion in a Scramjet Engine

Abstract

O PERATION of a scramjet engine involves many gas dynamic and combustion phenomena. The components of a scramjet engine, such as the intake, isolator, fuel injector, and flame holder, interact with each other in a complicated manner and may result in successful engine operation or fall into intake unstart, misfire, blowout, or thermal choking. Much of the previous experimental research on scramjets focuses on a single component, and examples of experimental research on the integrated intake, isolator, and combustor are fewer.Moreover, much research uses impact facilities, i.e., shock tubes or shock tunnels, and sometimes they cannot represent real operational conditions of the scramjet engine. For an example, some research shows that the scramjet intake starts more easily in impact facilities than in continuous facilities [1]. In this study, the effect of the combustor configuration on the flow and combustion in a scramjet engine is explored experimentally. A blowdown freejet-type continuous facility is used.A scramjet engine, in an integrated form of an intake, isolator, and combustor, is used as the test model. Fuel injector, cavity flame holder, and combustor configurations are changed for respective experiments. Through this experiment, some aspects of the relationships between the scramjet engine injector, cavity, and combustor configuration and the operational characteristics such as intake starts and unstarts, supersonic combustion, and combustion-driven unstarts are brought to light.