Effects of piston bowl geometry on combustion and emissions characteristics of a natural gas/diesel RCCI engine
Effects of piston bowl geometry on combustion and emissions characteristics of a natural gas/diesel RCCI engine
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DOI：
10.1016/j.applthermaleng.2016.03.162
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发表时间：
2015-10
影响因子：
6.4
通讯作者：
A. Kakaee;Ali Nasiri-Toosi;Babak Partovi;A. Paykani
中科院分区：
文献类型：
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作者：
A. Kakaee;Ali Nasiri-Toosi;Babak Partovi;A. Paykani
活塞凹腔的几何形状对反应性控制压燃（RCCI）发动机的燃烧和排放特性至关重要。本数值研究探讨了活塞碗几何形状对天然气/柴油RCCI性能和排放的影响，在中等负荷的发动机。采用二次喷射策略，在压缩比为16.1：1的条件下，选择了粗腔、缸腔和圆柱腔三种不同的活塞碗形状，研究了发动机转速、活塞碗深度和倒角环台对活塞碗形状的影响。结果表明，在低转速下，凹型对RCCI发动机的燃烧没有影响，但在高转速下，凹型对RCCI发动机的燃烧有显著影响。获得的结果还表明，浴缸式设计在较高的速度下产生最佳的性能和排放。据报道，活塞碗深度和倒角环土地也可以影响发动机排放，特别是UHC和CO排放。
Piston bowl geometries are crucial to the combustion and emission characteristics of reactivity controlled compression ignition (RCCI) engines. The present numerical study explores the effects of piston bowl geometry on natural gas/diesel RCCI performance and emissions at medium engine load. Three different piston bowl geometries including stock, bathtub and cylindrical with constant compression ratio 16.1:1 are selected using double injection strategy and influences of engine speed, piston bowl depth and chamfered ring-land are investigated. It is found that the bowl profile does not affect combustion of RCCI engine at low engine speeds, but it has much considerable effect at higher engine speeds. The results obtained also show that bathtub design yields the best performance and emissions at higher speeds. It is also reported that both piston bowl depth and chamfered ring-land can also affect engine-out emissions specially UHC and CO emissions.