Abstract Under the stress of environmental pollutions and fossil fuel consumption caused by on-road transport, hybrid vehicles are attracting much attention. Opposed rotary piston (ORP) engines are a promising power source for hybrid vehicles, due to their compact designs and high power density. In this paper, combustion and emission characteristics of a turbocharged ORP engine fuelled with hydrogen were investigated to evaluate the overall performance of this engine. The results indicated that volumetric efficiency of this ORP engine was higher than 89.0% for all the given cases. Peak in-cylinder pressure was in the range of 51.0 ~ 69.0 bar; and 4000 RPM scenario had the maximum value, being benefitted from high intake temperature and pressure, and high volumetric efficiency. Combustion duration of this engine ranged 27 ~ 43° crank angle (CA), and combustion phase happened at 7.5 ~ 13°CA after top dead centre (TDC). Peak nitrogen monoxide (NO) formation rates were corresponding to 5 ~ 13°CA after TDC; accumulated NO decreased slightly after reaching the peak value for low engine speed conditions. Discharge pressure at the start of the exhaust stroke was higher than 6.0 bar, especially for 5000 RPM case whose value was approximately 11.0 bar. This ORP engine presented excellent torque characteristics, and the maximum indicated power density was approximately 104.0 kW·L−1 which was much higher than turbocharged four-stroke reciprocating engines fuelled with gasoline.

中文翻译：

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大开节气门条件下氢燃料涡轮增压对置旋转活塞发动机燃烧和NOx排放特性的数值模拟

摘要 在道路交通带来的环境污染和化石燃料消耗的压力下，混合动力汽车备受关注。由于其紧凑的设计和高功率密度，对置旋转活塞 (ORP) 发动机是混合动力汽车的一种很有前途的动力源。在本文中，研究了以氢为燃料的涡轮增压 ORP 发动机的燃烧和排放特性，以评估该发动机的整体性能。结果表明，在所有给定情况下，该 ORP 发动机的容积效率均高于 89.0%。峰值缸内压力在 51.0 ~ 69.0 bar 范围内；4000 RPM 方案的最大值，受益于高进气温度和压力，以及高容积效率。该发动机的燃烧持续时间范围为 27 ~ 43° 曲柄角 (CA)，燃烧阶段发生在上止点（TDC）后的 7.5 ~ 13°CA。一氧化氮 (NO) 生成速率峰值对应于 TDC 后 5 ~ 13°CA；在达到低发动机转速条件下的峰值后，累积 NO 略有下降。排气冲程开始时的排气压力高于 6.0 bar，尤其是在 5000 RPM 的情况下，其值约为 11.0 bar。该ORP发动机具有优异的扭矩特性，最大指示功率密度约为104.0 kW·L-1，远高于以汽油为燃料的涡轮增压四冲程往复式发动机。在达到低发动机转速条件下的峰值后，累积 NO 略有下降。排气冲程开始时的排气压力高于 6.0 bar，尤其是在 5000 RPM 的情况下，其值约为 11.0 bar。该ORP发动机具有优异的扭矩特性，最大指示功率密度约为104.0 kW·L-1，远高于以汽油为燃料的涡轮增压四冲程往复式发动机。在达到低发动机转速条件下的峰值后，累积 NO 略有下降。排气冲程开始时的排气压力高于 6.0 bar，尤其是在 5000 RPM 的情况下，其值约为 11.0 bar。该ORP发动机具有优异的扭矩特性，最大指示功率密度约为104.0 kW·L-1，远高于以汽油为燃料的涡轮增压四冲程往复式发动机。