Assessment of flamelet versus multi-zone combustion modeling approaches for stratified-charge compression ignition engines
Assessment of flamelet versus multi-zone combustion modeling approaches for stratified-charge compression ignition engines
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DOI：
10.1177/1468087415571006
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发表时间：
2016-03
影响因子：
2.5
通讯作者：
P. Pal;SeungHwan Keum;H. Im
中科院分区：
文献类型：
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作者：
P. Pal;SeungHwan Keum;H. Im
采用喷雾相互作用小火焰模型和扩展多区燃烧模型，结合多维计算流体力学，研究了低负荷条件下直喷压燃式发动机充量分层的影响。进行了参数研究，以比较这两种方法的早期和后期的燃油喷射正时。数值计算结果与现有的实验数据的比较表明，对于早期燃料喷射，两种模型预测的自燃和燃烧特性具有可比的保真度。然而，作为燃料喷射定时延迟，喷雾相互作用的小火焰模型被发现捕获的燃烧和随后的热释放的发病具有更高的精度。进一步的研究表明，喷雾相互作用的火焰面模型在更广泛的混合物分层条件下的更好的性能，主要是由于它能够捕捉到的扩散传输所产生的小尺度混合和毒性化学相互作用，这变得更加重要时，显着的混合物不均匀性存在于发动机气缸。
The spray-interactive flamelet and extended multi-zone combustion models coupled with multi-dimensional computational fluid dynamics are applied to investigate the effects of charge stratification in a direct-injection compression ignition engine under low load conditions. A parametric study was carried out in order to compare the two approaches for early and late fuel injection timings. Comparison of numerical results with available experimental data shows that for early fuel injection, both models predict the auto-ignition and combustion characteristics with comparable fidelity. As the fuel injection timing is delayed, however, the spray-interactive flamelet model is found to capture the onset of combustion and subsequent heat release with greater accuracy. Further investigation reveals that the better performance of the spray-interactive flamelet model over a wider range of mixture-stratified conditions is mainly attributed to its ability to capture the diffusive transport resulting from small-scale mixing and turbulence–chemistry interaction, which becomes more important when significant mixture inhomogeneities exist in the engine cylinder.