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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2016, Vol. 37 ›› Issue (S1): 112-118.doi: 10.7527/S1000-6893.2016.0149

• Propulsion System • Previous Articles     Next Articles

Unsteady combustion process in multi-cavity combustor at low Mach number condition

WANG Lu1,2, GAO Liangjie1,2, QIAN Zhansen1,2, ZHAO Yong1,2   

  1. 1. AVIC Aerodynamic Research Institute, Shenyang 110034, China;
    2. Aeronautical Science and Technology Key Lab for High Speed and High Reynolds Number Aerodynamic Force Research, Shenyang 110034, China
  • Received:2016-04-23 Revised:2016-05-13 Online:2017-01-10 Published:2016-05-30
  • Supported by:

    Aeronsutical Science Foundation of China (2014ZA27010)

Abstract:

As one of the most effective structures of flame stabilizer, cavity plays an important role in the research on ramjet combustors. Flow field characteristics of the kerosene-fueled multi-cavity ramjet combustor are analyzed without and with combustion in this paper. The unsteady combustion flow field in the combustor is discussed in particular at the initial stage of ignition start-up at low inlet Mach numbers. The results show that the fuel residence time is increased by the bigger vortex in the upstream cavity. The unburned fuel is blown off to the downstream cavity for a further combustion as soon as it meets the high-speed main stream, which is helpful to improve combustion efficiency. The mass of kerosene drifted into cavities is determined by fuel-jet velocity, which would have an indirect effect on the combustion efficiency. At the beginning of the ignition start-up, the phenomena of mainstream blowout, countercurrent flame propagation and mainstream reburning appeared in the unsteady numerical study. The mechanisms of the countercurrent flame propagation are both slow reaction in first cavity and the downstream heat release.

Key words: low Mach number, multi-cavity combustor, unsteady combustion, numerical simulation, jet

CLC Number: