柴油机活塞振荡冷却过程射流流动与过冷沸腾传热机理研究

项目名称： 柴油机活塞振荡冷却过程射流流动与过冷沸腾传热机理研究

项目编号： No.51206031

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 工程热物理与能源利用学科

项目作者： 明平剑

作者单位： 哈尔滨工程大学

项目金额： 25万元

中文摘要： 大功率船用柴油机活塞的高效冷却问题是先进柴油机活塞设计的关键问题之一。活塞振荡冷却效率高，并且被广泛采用。振荡冷却效果受到很多因素影响，针对这一问题国内外开展了大量的研究。目前研究主要针对传热系数计算方法和活塞结构变化对温度分布的影响，活塞工作过程中冷却液受到的活塞往复激励、浮力效应和惯性力相互耦合作用实验研究等，而理论研究匮乏。本课题拟基于双尺度大涡模拟技术模拟液体射流卷吸、两相界面相互作用，建立液体射流冷却数值仿真平台，考虑结构表面局部沸腾效应，探索湍流细节和往复激励下冷却液传热机理。主要研究内容：（1）建立过冷液体射流冲击高温壁面过程中的流动和传热模型（2）探索往复激励下冷却剂射流过程的流动和传热模式（3）分析过冷液体冲击高温结构局部沸腾和热流耦合作用（4）揭示往复激励与时变热流作用下的冷却流动和传热特性。

中文关键词： 冲击射流；振荡冷却；湍流模型；往复激励；传热特性

英文摘要： Highly efficient cooling of heavy duty marine diesel engine piston is one of the key parts of modern advanced engine piston design. Due to high efficience of shaker cooling system, it is extensively used. While it is influenced by many factors, lots of research work has been done on this problem. Most researches are focused on calculation method of heat transfer coefficients or effects of different piston structures on temperature distribution. Rare work has been done on coolant flow in piston under coupling of reciprocating,buoyance and inertial force until now. Because RANS method is difficult to capture the details of turbulence, a new numerical method based two-scale LES method will be developed in this project. Oil impingingment and local boiling of subcooling coolant effects will be taken into account by a coupled VOF and Eulerian-Eulerian two fluid method. The main contains of this research are followed:(1)Develop flow and heat transfer model for the process of subcooling coolant impingingment on high temperature structure;(2)Explore fluid flow and heat transfer model under reciprocating action; (3)Analysis of local boiling ang thermal fluid flow coupling with subcooling coolant impingingment on high temperature structure; (4)Unveil fluid flow and heat transfer characteristics under reciprocating and tim

英文关键词： impinging jet；shaker cooling；turbulence model；reciprocating motion；impingement heat transfer