Characterizing hydrogen-fuelled pulsating combustion on thermodynamic properties of a combustor

Abstract

Unlike hydrocarbon fuel, hydrogen is ‘green’ and attracting more and more attentions in energy and propulsion sectors due to the zero emission of CO and CO2. By applying numerical simulations, we explore the physics of how a hydrogen-burnt flame can sustain pulsating combustion and its impact on the thermodynamic properties of a standing-wave combustor. We also explain how implementing a heat exchanger can mitigate such pulsating combustion. The dynamic interactions of the unsteady flow-flame-acoustics-heater are examined by varying the mass flow rate ṁH2 and the heating bands’ surface temperature TH. The frequency and amplitude of the pulsating combustion are shown to depend strongly on ṁH2. In addition, varying TH is shown to lead to not only the molar fraction of the combustion species being changed but also the flame-sustained pulsating oscillations being mitigated somehow. Finally, nonlinearity is observed and identified in the unsteady flow velocity and the two heat sources.