Mixing and combustion characteristics in a cavity-based supersonic combustor with different injection schemes

• Published in: Acta astronautica 2019-06, Vol.159, p.584-592
• Main Authors: Song, Xiliang, Wang, Hongbo, Sun, Mingbo, Cai, Zun, Liu, Chaoyang, Yu, Jiangfei
• Format: Article
• Language: English
• Subjects: Combustion; Combustion chambers; Computer simulation; Equivalence ratio; Flamebase oscillations; Inflow; Injection; Injection schemes; Numerical simulations; Orifices; Shear layers; Stagnation pressure; Stagnation temperature; Supersonic combustion ramjet engines; Supersonic flow
• ISSN: 0094-5765; 1879-2030
• DOI: 10.1016/j.actaastro.2019.02.012

Mixing and combustion characteristics in an ethylene fueled cavity-based scramjet combustor with different injection schemes are investigated experimentally and numerically in low equivalence ratio conditions, with inflow conditions of Ma = 2.52, stagnation pressure P0 = 1.65 MPa and stagnation temperature T0 = 1600 K. The wall-pressure distributions obtained by numerical simulations are in fairly good agreement with the experimental data. The numerical results also indicate that multiple-orifice cases have higher mixing efficiencies and combustion efficiencies than single-orifice cases. In addition, it is observed in the experiments that flamebases are not stabilized in a fixed position. In single-orifice cases, the flamebases oscillate dramatically between the cavity leading edge and trailing edge, and the oscillations are similar for different injection pressures. In multiple-orifice cases, the flamebases oscillate slightly in the cavity shear layer just downstream of the leading edge and the amplitudes with lower injection pressure are larger than those with higher injection pressure. •Low equivalence ratio cavity flames in a supersonic flow are studied.•Parallel multiple-orifices injections are compared with single-orifice injections.•Flamebase oscillations with different injection schemes are firstly studied.