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Acta Aeronautica et Astronautica Sinica ›› 2024, Vol. 45 ›› Issue (19): 30027.doi: 10.7527/S1000-6893.2024.30027

Special Issue: 冲压发动机

• Reviews • Previous Articles    

Vitiation effects on scramjet operational characteristics

Wen SHI, Jialing LE, Ye TIAN()   

  1. Aerospace Technology Institute,China Aerodynamics Research and Development Center,Mianyang 621000,China
  • Received:2023-12-27 Revised:2024-02-01 Accepted:2024-03-07 Online:2024-03-21 Published:2024-03-19
  • Contact: Ye TIAN E-mail:tianye@cardc.cn
  • Supported by:
    National Level Project

Abstract:

Characteristics of internal flow and combustion in the scramjet engine have been constantly and extensively investigated, with experimental research strongly reliant on the combustion heated facilities. The combustion of fuels such as alcohol, hydrogen, and kerosene is able to heat the tested gas to the designed conditions, and the mole fraction of oxygen is ensured by the oxygen supplementation. Meanwhile, the combustion of fuels inevitably imports multiple vitiated air contaminants, the existence of which in the combustion heated facilities deviates the ground-test results from those obtained in the actual atmospheric flight conditions. Vitiation effects thus become an urgent problem to solve for improving the accuracy of ground-test result extrapolation. This paper comprehensively reviews five typical aspects, including the vitiation effects on ignition characteristics, scramjet performance, combustion mode transition, typical flow-parameter-matching scheme, and vitiation effect correction. The research progress of vitiation effects has also been introduced.The results show that in most cases, the vitiation component H2O will reduce the ignition delay time and promote fuel ignition, CO2 will inhibit combustion and free radicals and intermediates will significantly promote ignition for methane, ethylene, kerosene and other fuels. The inhibition effect of CO2 on combustion is more significant than that of H2O with the same mole fraction, and the inhibition effect shows a nonlinear trend. At present, the parameter matching schemes commonly used are difficult to reduce the vitiation effects, that is, the deviation of the results obtained from the ground test and the real flight test in the wide range of velocity and equivalent ratio. The correction of vitiation effects is still difficult to achieve.

Key words: scramjet, vitiation component, ignition characteristics, combustion mode transition, flow-parameter-matching scheme, vitiation effect correction

CLC Number: