当前位置: X-MOL 学术Flow Turbulence Combust. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Investigation of Engine Combustion and Auto-ignition of a Multicomponent Surrogate Fuel with NTC Behavior Under Knocking Conditions
Flow, Turbulence and Combustion ( IF 2.0 ) Pub Date : 2022-08-08 , DOI: 10.1007/s10494-022-00351-9
Magnus Kircher , Sebastian Popp , Sandro Gierth , Andrea Pati , Jonathan Schneider , Marco Günther , Christian Hasse

The occurrence of knocking combustion is limiting the efficiency of modern spark ignition engine operation. Thus, an understanding of the processes at the knock limit is required for further optimization of the combustion process. In this work, the combustion of a multicomponent Toluene Reference Fuel (TRF) in a single-cylinder research engine is investigated under knocking conditions. The fuel exhibits a negative temperature coefficient (NTC) regime for thermodynamic conditions relevant to the engine operation. A precursor model is used to capture the auto-ignition process. Under homogeneous conditions, a two-stage auto-ignition is observed. Inside the NTC regime, the temperature affects both first-stage and second-stage auto-ignition delay times. With a subsequently conducted multi-cycle engine LES, the effects of temperature stratification and turbulent flame propagation on the local auto-ignition process are investigated. It is observed, that the NTC behavior leads to a widespread two-stage auto-ignition. The knock intensity observed in the experiments is directly related to the mass consumed by auto-ignition. This is due to the fast consumption of the auto-ignited mass by the flame front. With that, the NTC behavior affects the local auto-ignition process in the unburned mixture while the flame propagation determines the knock intensity for the operating conditions at the knock limit.



中文翻译:

爆震条件下具有 NTC 行为的多组分替代燃料的发动机燃烧和自燃研究

爆震燃烧的发生限制了现代火花点火发动机运行的效率。因此,为了进一步优化燃烧过程,需要了解爆震极限处的过程。在这项工作中,研究了单缸研究发动机中多组分甲苯参考燃料 (TRF) 在爆震条件下的燃烧。对于与发动机运行相关的热力学条件,燃料表现出负温度系数 (NTC) 状态。前体模型用于捕获自燃过程。在均质条件下,观察到两阶段自燃。在 NTC 范围内,温度会影响第一阶段和第二阶段的自燃延迟时间。使用随后进行的多循环发动机 LES,研究了温度分层和湍流火焰传播对局部自燃过程的影响。据观察,NTC 行为导致广泛的两阶段自动点火。实验中观察到的爆震强度与自燃消耗的质量直接相关。这是由于火焰前沿快速消耗自燃物质。因此,NTC 行为会影响未燃烧混合物中的局部自燃过程,而火焰传播决定了爆震极限工况下的爆震强度。实验中观察到的爆震强度与自燃消耗的质量直接相关。这是由于火焰前沿快速消耗自燃物质。因此,NTC 行为会影响未燃烧混合物中的局部自燃过程,而火焰传播决定了爆震极限工况下的爆震强度。实验中观察到的爆震强度与自燃消耗的质量直接相关。这是由于火焰前沿快速消耗自燃物质。因此,NTC 行为会影响未燃烧混合物中的局部自燃过程,而火焰传播决定了爆震极限工况下的爆震强度。

更新日期:2022-08-09
down
wechat
bug