Establishment of an improved heat transfer model based on an enhanced thermal wall function for internal combustion engines operated under different combustion modes
发表时间：2019-10-13
点击次数：
- 论文类型：
- 期刊论文
- 第一作者：
- Cao, Jingjie
- 通讯作者：
- Jia, M (reprint author), Dalian Univ Technol, Key Lab Ocean Energy Utilizat & Energy Conservat, Minist Educ, Dalian 116024, Peoples R China.
- 合写作者：
- Jia, Ming,Niu, Bo,Chang, Yachao,Xu, Zhen,Liu, Hong
- 发表时间：
- 2019-09-01
- 发表刊物：
- ENERGY CONVERSION AND MANAGEMENT
- 收录刊物：
- SCIE、EI
- 文献类型：
- J
- 卷号：
- 195
- 页面范围：
- 748-759
- ISSN号：
- 0196-8904
- 关键字：
- Heat transfer; Thermal wall function; In-cylinder turbulence; Prandtl number; Internal combustion engine
- 摘要：
- The heat transfer from the in-cylinder gases to the wall dramatically affects the combustion and emission characteristics of internal combustion engines, particularly for the engines operated with advanced low-temperature combustion modes. In the present work, an improved heat transfer model was established based on an enhanced thermal wall function using the piecewise functions, in which only the laminar Prandtl number is considered in the viscous sublayer, and the competition between the laminar Prandtl number and the turbulent Prandtl number is taken into account in the buffer layer and turbulent core regions. By implementing the improved heat transfer model into a computational fluid dynamics code, the predictions of the combustion processes and the heat transfer behaviors of an engine operated with conventional diesel combustion, homogeneous charge compression ignition, and reactivity controlled compression ignition modes were validated by the experimental data. Moreover, the computational results from two previous heat transfer models, i.e., Han and Reitz model and Rakopoulos et al. model, were presented for comparison. The results indicate that the heat flux characteristics under different combustion modes can be more satisfactorily reproduced using the improved heat transfer model than Han and Reitz model and Rakopoulos et al, model by avoiding the flaws in the thermal wall function. Finally, the influence of the dimensionless distance of the computational grid adjacent to the wall on the predicted heat flux was discussed to study the dependence of the heat transfer model on the size of the near wall computational grid.
- 是否译文：
- 否
- 上一条：Kinetic modeling study of homogeneous ignition of dimethyl ether/hydrogen and dimethyl ether/methane
- 下一条：Evaluation of variable compression ratio (VCR) and variable valve timing (VVT) strategies in a heavy-duty diesel engine with reactivity controlled compression ignition (RCCI) combustion under a wide load range
