Flow and Temperature Distribution in an Experimental Engine: LES Studies and Thermographic Imaging
Flow and Temperature Distribution in an Experimental Engine: LES Studies and Thermographic Imaging
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DOI：
10.4271/2010-01-2237
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发表时间：
2010-10
期刊：
影响因子：
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通讯作者：
T. Joelsson;R. Yu;X. Bai;N. Takada;Ischiro Sakata;H. Yanagihara;J. Lindén;M. Richter;M. Aldén;B. Johansson
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文献类型：
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作者：
T. Joelsson;R. Yu;X. Bai;N. Takada;Ischiro Sakata;H. Yanagihara;J. Lindén;M. Richter;M. Aldén;B. Johansson
温度分层在HCCI燃烧过程中起着重要作用。发动机缸内温度场对自燃起始点和燃烧持续期的影响很敏感。壁面边界条件对HCCI发动机燃烧过程的数值模拟有重要影响，尤其是缸壁和活塞壁面的温度条件。本文报道了一台光学实验发动机在机动运行条件下的温度场的数值研究和实验，旨在提高对缸内温度分层演变的理解。数值模拟采用大涡模拟方法，解决了非定常大涡和大尺度旋涡、滚流结构。利用激光诱导磷光进行了二维温度实验，将热成像荧光粉接种到气缸中的气体中。结果表明，温度分层的发展不同的机制：进气和残余气体的混合，在壁边界层的传热，压缩的电荷，和大规模的流动传输。分析了大涡模拟结果对不同壁面边界条件和来流条件的敏感性。（减）
Temperature stratification plays an important role in HCCI combustion. The onsets of auto-ignition and combustion duration are sensitive to the temperature field in the engine cylinder. Numerical simulations of HCCI engine combustion are affected by the use of wall boundary conditions, especially the temperature condition at the cylinder and piston walls. This paper reports on numerical studies and experiments of the temperature field in an optical experimental engine in motored run conditions aiming at improved understanding of the evolution of temperature stratification in the cylinder. The simulations were based on Large-Eddy-Simulation approach which resolves the unsteady energetic large eddy and large scale swirl and tumble structures. Two dimensional temperature experiments were carried out using laser induced phosphorescence with thermographic phosphors seeded to the gas in the cylinder. The results revealed different mechanisms for the development of temperature stratification: intake gas and residual gas mixing, heat transfer in the wall boundary layer, compression of the charge, and large scale flow transport. The sensitivity of LES results to different wall boundary conditions and inflow conditions was analyzed. (Less)