Study on vortex dynamics of hydrogen/methane flame under rigid-flexible construction coupling effects

Abstract

This study investigated the evolution characteristics of flame vortex and explosion overpressure with different hydrogen ratio under rigid and flexible constructions. The results indicated that the coupling effect generated in the case of rigid and flexible constructions can suppressed the propagation of flame, increased vortex size, spiral motion, and collision fusion efficiency. The time of flame velocity peak will be advanced with the increased of hydrogen ratio. When the hydrogen ratio is 10%, 20%, 30%, it increased by −4.67%, 18.07% and 30.75%, respectively, compared to when the hydrogen ratio is 0%.Under the same fuel concentration, the oscillation attenuation duration of overpressure peak gradually decreased under the two types of construction arrangements. Under the same construction layout, an increase in hydrogen concentration leads to an increase in maximum explosion overpressure and an earlier occurrence time. The maximum explosion overpressure peak attenuation ratio in the case of rigid and flexible constructions upstream is 13.02%. The coupling effect of rigid and flexible structures increases the heat consumption during combustion to achieve the purpose of explosion suppression.