Investigation of Dual-Vortical-Flow Hybrid Rocket Engine without Flame Holding Mechanism

• Published in: International journal of aerospace engineering 2018-01, Vol.2018 (2018), p.1-13
• Main Authors: Wu, J.-S., Lin, J.-W., Wei, S.-S., Chou, T.-H., Lai, A., Chen, Y.-S.
• Format: Article
• Language: English
• Subjects: Aerospace engineering; Design; Efficiency; Fluid dynamics; Fuels; High density polyethylenes; Mathematical models; Nitrous oxide; Numerical analysis; Pressure oscillations; Propulsion systems; Reacting flow; Rocket engines; Rockets; Swirling; Turbulence models
• ISSN: 1687-5966; 1687-5974
• DOI: 10.1155/2018/6513084

A 250 kgf thrust hybrid rocket engine was designed, tested, and verified in this work. Due to the injection and flow pattern of this engine, this engine was named dual-vortical-flow engine. This propulsion system uses N2O as oxidizer and HDPE as fuel. This engine was numerically investigated using a CFD tool that can handle reacting flow with finite-rate chemistry and coupled with the real-fluid model. The engine was further verified via a hot-fire test for 12 s. The ground Isp of the engine was 232 s and 221 s for numerical and hot-fire tests, respectively. An oscillation frequency with an order of 100 Hz was observed in both numerical and hot-fire tests with less than 5% of pressure oscillation. Swirling pattern on the fuel surface was also observed in both numerical and hot-fire test, which proves that this swirling dual-vortical-flow engine works exactly as designed. The averaged regression rate of the fuel surface was found to be 0.6~0.8 mm/s at the surface of disk walls and 1.5~1.7 mm/s at the surface of central core of the fuel grain.