Numerical investigation of the configuration effects to the Ejector-jet Performance in the RBCC engine combustor model
- Paper number
IAC-08.C4.5.10
- Author
Dr. Susumu Hasegawa, Japan Aerospace Exploration Agency (JAXA), Japan
- Year
2008
- Abstract
To reduce the required propellant mass fraction for space transportation vehicles, the use of atmospheric air is one of the most promising options. Recently rocket based air-breathing concepts, so-called Rocket Based Combined Cycle (RBCC) engines have received increasing attention. RBCC engines are being studied in Kakuda Space Center, a division of Japan Aerospace Exploration Agency (JAXA). In addition to the plane rocket exit, by slicing off the rocket exit plane obliquely, additional two rockets called convex and concave were invented by Tani et al.[1] Tani et al. conducted series of small scale tests of the RBCC engine, and the ejector performance was improved with high rocket pressure regime in case of concave rocket. In order to get a better understanding of the experiments and obtain more reliable performance estimations of the RBCC engine in an ejector-jet mode, numerical simulation was carried out using the CFD code developed in-house for unstructured grids. To predict the suction performance of the ejector driven by rocket gases, numerical domains were set up both inside and outside domains of the engine combustor model. CFD replicated the basic flow structures in regard with shock waves on the top wall side and the subsonic flows on the cowl side. In general, the current model created two-layered flow; one was induced subsonic air flow and the other was a rocket exhaust which is supersonic to some extent. The calculated pressures show good agreements with our experiments [2]. To reproduce the experimental results, numerical simulations with three rocket configurations in the rocket pressure range from 0.6MPa to 2.5MPa were conducted and the suction performances were obtained. Numerical simulations in case of concave rocket configuration also showed the improved ejector performance in high pressure regime and flow fields were analyzed. It was found that in case of concave air and rocket flow formed a single flow and entire flow achieved supersonic state. In addition to the configurations conducted in the experiments, parametric studies of configurations including various concave angels were studied. The detail of this research is to be presented in the conference. 1) Tani, K., Kato, K., Hasegawa, S., “Flow Visualization in an Ejector-Jet Mode of Combined Cycle Engine,” Proc. of 39th Japanese Congress of Fluid Mechanics. 2) Hasegawa, S., Tani, K., “Effects to the Ejector-jet Performance by the Physical Conditions of Rocket Gas in the RBCC configuration,” Asian Joint Conference on Propulsion Power 2008
- Abstract document
- Manuscript document
IAC-08.C4.5.10.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.