Abstract
A widely applicable and variable geometry 2-D rocket based combined cycle (RBCC) inlet characterized by the dual-duct design is conceptually put forward. The inlet operates as dual-duct status in the low Mach range (0~4), and transits to single-flowpath status in the following high Mach range (4~7). It accomplishes operational status transition through an 8.0-degree ramp rotation and a 4.0-degree cowl rotation at Mach 4. Through numerical simulations on typical flight Mach numbers, the observed starting Mach number is 2.2, which provides a sufficient operational window for a smooth ejector-to-ramjet mode transition. The RBCC inlet achieves comprehensive high mass capture coefficients in the overall wide flight range, especially in the low speed regimes. Suitable Mach numbers satisfying various combustion requirements in different modes together with high total pressure recovery coefficients are also obtained since the physical throat areas, compression angles, and the corresponding contraction ratios can be adjusted by a large margin through very limited rotations. The variable geometry scheme is not only feasible for practical realizations, but is also simple to arrange the dynamic sealing issues in a low-temperature environment in the RBCC engine.
Funding statement: National Natural Science Foundation of China, (Grant / Award Number: ‘51606156’).
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China through grant 51606156.
Nomenclature
- M∞
flight Mach number
- Mout
Mach number at exit of RBCC inlet
- Mstart
starting Mach number of RBCC inlet
- P
static pressure along flowpath, Pa
- P∞
static pressure of incoming flow, Pa
- Φ
air capture mass coefficient
- σ
total pressure recovery coefficient
- x
x-value along flow path, mm
- Hc
capture height of RBCC inlet, mm
- Δ
throttling degree of 2-D supersonic inlet
References
1. Etele J, Hasegawa S, Ueda S. Experimental investigation of an alternative rocket configuration for rocket-based combined cycle engines. J Power Energy 2014;30(4):944–951.10.2514/1.B35080Search in Google Scholar
2. Kodera M, Ueda S. Numerical analysis of transient phenomena to Ramjet mode in a RBCC combustor, AIAA paper 2015–3591, 2015.10.2514/6.2015-3591Search in Google Scholar
3. Stemler JN, Bogar TJ, Farrell DJ, Bulman MJ, Hunt JL. Assessment of RBCC-powered VTHL SSTO vehicles, AIAA paper 1999–4947, 1999.10.2514/6.1999-4947Search in Google Scholar
4. Bulman M, Siebenhaar A. The strutjet engine–exploding the myths surrounding high speed airbreathing propulsion, AIAA paper 1995–2475, 1995.10.2514/6.1995-2475Search in Google Scholar
5. Siebenhaar A, Bulman M.The strutjet engine: the overlooked option for space launch, AIAA paper 1995–3124, 1995.10.2514/6.1995-3124Search in Google Scholar
6. Bossard JA. Propulsion efficiency considerations for combined cycle propulsion systems, AIAA paper 2015–3943, 2015.10.2514/6.2015-3943Search in Google Scholar
7. Fujikawa T, Tsuchiya T, Tomioka S. Multi-objective, multidisciplinary design optimization of TSTO space planes with RBCC engines, AIAA paper 2015–0650, 2015.10.2514/6.2015-0650Search in Google Scholar
8. Kouchi T, Kobayashi K, Kudo K, Murakami A, Kato K, Tomioka S. Performance of a RBCC combustor operating in ramjet mode, AIAA paper 2006–4867, 2006.10.2514/6.2006-4867Search in Google Scholar
9. Kato K, Kanda T, Kudo K, Murakami A. Experimental study of combined cycle engine combustor in scramjet-mode, AIAA paper 2005–3316, 2005.10.2514/6.2005-3316Search in Google Scholar
10. Takegoshi M, Tomioka S, Ueda S, Saito T, Izumikawa M. Performances of a rocket chamber for the combined-cycle engine at various conditions, AIAA paper 2006–7978, 2006.10.2514/6.2006-7978Search in Google Scholar
11. Trefny CJ. An air-breathing launch vehicle concept for sing-stage-to-orbit, AIAA paper 1999–2730, 1999.10.2514/6.1999-2730Search in Google Scholar
12. Donald T. Palac, NASA Glen Research Center’s hypersonic propulsion program, Report NASA/TM-1999-209185, 1999.Search in Google Scholar
13. Tomioka S, Takegoshi M, Kudo K, Kato K, Hasegawa S, Kobayashi K. Performance of a rocket-ramjet combined-cycle engine model in engine model in ejector mode operation, AIAA paper 2008–2618, 2008.10.2514/6.2008-2618Search in Google Scholar
14. Kanda T, Tomioka S, Ueda S, Tani K. Design of sub-scale rocket-ramjet combined cycle engine model, IAC- 05- C4. 5. 03.Search in Google Scholar
15. Quinn JE. Oxidizer selection for the ISTAR program (Liquid Oxygen versus Hydrogen Peroxide), AIAA paper 2002–4206, 2002.10.2514/6.2002-4206Search in Google Scholar
16. Xiaowei L. Investigation of wide applicability inlet for RBCC power. Ph.D. Dissertation, Northwestern Polytechnical University, 2010. (in Chinese).Search in Google Scholar
17. Hao Z. Research on variable geometry inlet and Nozzle of RBCC engine. Master Dissertation, Northwestern Polytechnical University, 2013. (in Chinese).Search in Google Scholar
18. Shi L, He G, Qin F, Wei X. Numerical study of a boundary layer bleed for a rocket-based combined-cycle inlet in ejector mode. Int J Turbo Jet Engines 2014;31(4):347–359.10.1515/tjj-2014-0006Search in Google Scholar
19. Yong Y, Junming Z, Liantian J. FLUENT introductory and advanced tutorial, 6.3 UDF manual, Beijing Institute of Technology Press, 2012.Search in Google Scholar
20. Herrmann CD, Koschel WW. Aerodynamic performance analysis of a hypersonic inlet, AIAA paper 2002–4130, 2002.Search in Google Scholar
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