航空氨氢转子发动机燃烧仿真分析OA

To investigate the influence mechanism of hydrogen blending ratios on combustion characteristics of an aviation ammonia-hydrogen rotary engine under high-altitude conditions,a three-dimensional simulation model was developed in CONVERGE based on an in-cylinder swash-plate rotary engine.This model was employed to analyze combustion and emission processes at hydrogen blending ratios of 13％～29％under constant operating condition,i.e.6 000 m altitude,6 000 r/min engine speed,1.2 equivalence ratio and-20° ignition timing.Simulation results showed that increasing hydrogen blending ratios significantly improved the flame propagation velocity.The peak in-cylinder pressure increased from 2.7 MPa at 13％hydrogen blending ratio to 6.3 MPa at 29％hydrogen blending ratio,and the peak exothermic rate increased from 3 J/(°)to 23 J/(°).The combustion duration was shortened,and the generation of NO increased with the increase in the hydrogen blending ratio,while the emissions of NO 2 and unburned ammonia decreased.Elevating hydrogen blending ratios can effectively optimize the combustion phase,and enhance the combustion stability,though increased NO emissions should be considered.