Experiment And Numerical Simulation Investigation Of Dual-Mode Scramjet

Experimental and numerical methods were conducted in study the Dual-mode Scramjet(DMS) and the subsonic combustion was translated into supersonic combustion, at the simulated condition, which corresponds the flying state of Ma=6,H=25km.The influence of fuel equivalence ratio, injection position, cavity flame holding ability, pre-injection pressure and wall temperature on the combustor pressure distribution were investigated and some methods of improving the combustor performances were found. The mode transition process, the influence of instant fuel equivalence ratio, and the characteristic of thermal choke and mechanism choke were studied, which achieved some conclusions of DMS, using the one-dimensional mode as an analysis tool. The dynamic process of ignition process, boundary layer separation and pressure instable were studied more closely. The Scramjet Experiment Database (SED) was designed, basing on all the experiment data, which worked well during data analysis.Numerical investigation of the experimental DMS configuration was performed, which proved the former theory of mixing combustion. The cavity flame holding mechanism was studied and come to the point that the character of cavity can be valued relying on the flow conditions. The boundary separation was studied in terms of wall temperature and DMS configuration. The ignition by hydrogen was investigated by numerical method, which explained the test phenomena perfectly.The results obtained in the thesis study on the DMS mechanism, cavity character, boundary separation, mechanism choke enhancing combustion and mode transition, and the practical SED provide reference to the future research and DMS design.