Investigation of effective fuel injection systems for scramjet model combustor with double pylon

Supersonic combustion technique is required for future hypersonic airplanes. Our research focused on an effective hydrogen fuel injection form for cavity flameholder with double pylon in supersonic flow. To achieve stable combustion under the conditions of low mainstream total temperature, both a pre-burnt gas injection from the pre-burning chamber at the bottom of the cavity and the main fuel injected from upstream the cavity, were combined. It is a method for fuel ignition. A wind tunnel experiment were performed at a condition of low total temperature of the mainstream. As a result, we achieved the increase of the wall pressure at the combustor using our new technique. In addition, a transition of using pure hydrogen by cutting down the supply of air for pre-burning chamber was studied and the rise of the wall pressure was also confirmed. Numerical simulations were carried out to compare the results to the experimental results. Model of flame holding mechanisms have been constructed from the simulation results.