Home – Home – Jornals – Combustion, Explosion and Shock Waves 2018 number 4

Regimes of continuous detonation of methane/hydrogen-air mixtures in spin and opposing transverse detonation waves are obtained for the first time in a flow-type annular cylindrical combustor 503 mm in diameter. A two-component (methane/hydrogen) fuel with the H₂ mass fractions of 1/9-1/2 in the range of specific flow rates of the mixture from 64 to 1310 kg/(s × m²) and the fuel-to-air equivalence ratio φ = 0.78-1.56 is considered. In methane/hydrogen-air mixtures with two compositions of the fuel (CH₄ + H₂ and CH₄ + 4H₂) one-wave and two-wave regimes of continuous spin detonation are obtained; the frequency of rotation of transverse detonation waves is 0.56-1.66 kHz at φ = 0.78-1.02. For the fuel compositions CH₄ + 2H₂ and CH₄ + 1.5H₂, continuous multifront detonation with two opposing transverse detonation waves rotating with the frequency of 0.86-1.34 kHz at φ = 1.0-1.23 is obtained. For the CH₄ + H₂ + air mixture, both combustion in the chamber and continuous spin detonation outside the combustor with transverse detonation waves rotating with the frequency of 1.01-1.1 kHz are observed. The lean limits of continuous detonation are obtained in terms of the specific flow rate of the mixture: 64, 100, 200, and 790 kg/(s × m²) for the fuel compositions CH₄ + 8H₂, CH ₄ + 4H₂, CH₄ + 2H₂, and CH₄ + 1.5H₂, respectively, for the mass fraction of hydrogen in the methane/hydrogen fuel of ≈0.16. Violation of regularity of the continuous detonation wave structure and the wave velocity with a decrease in the fraction of hydrogen in the two-component fuel is detected.