导　　师： 李明海

学科专业： 080204

授予学位： 硕士

作　　者： ;

机构地区： 大连交通大学

摘　　要： 进气道结构直接影响内燃机缸内充量的大小和涡流的强弱,直接关系到混合气形成、燃烧、排放以及整机性能。传统气道研发采用经验设计和稳流试验相结合的方法,研制周期长,且难以得到理想方案。采用三维数值模拟研究进气道,不仅可以获得综合评价参数,而且可以得到气道内部流场的微观信息,为气道优化设计和改进提供重要依据。 本文综述了柴油机进气道的开发研究;选定了进气道流动的数学模型和数值方法;建立了YC6T柴油机螺旋进气道三维几何模型,利用气道稳流试验台的试验结果作边界条件,在AVL-FIRE软件中进行了三维数值模拟;按试验所得的Ricardo和FEV评价参数验证了计算结果,两者趋势吻合良好,验证了应用CFD评价气道的可行性;给出了气道详尽的流场信息,提出了气道改进建议;依气道改进建议改进了气道,并再次进行了数值模拟计算,与预期的目标吻合良好,验证了应用CFD改进气道的正确性。本文将流场分析结果直接应用于指导气道改进,达到见效快、降低开发成本的良好效果。 The structure of intake port directly affects the quantity of fresh air and the strength of swirl in cylinder and it can be related with forming mixture air and oil, combustion, exhaust and total performance of diesel engine. But the method of three-dimensional numerical simulation can offer the integration evaluating parameters of the intake port and can show the microcosmic information of the inner flow field. So this method can supply the optimization design and improvement for the intake port of diesel engine. In this dissertation, the development and research of diesel intake port is summarized and the mathematical models and numerical method are selected for three-dimensional numerical simulation.establishes the three-dimensional geometric model of the YC6T helical intake port and uses the results of steady flow test rig as boundary conditions;makes three-dimensional numerical simulations in CFD software AVL-FIRE,validates the calculational results via the Ricardo and FEV evaluation acquired through test rig,and draws a conclusion that the two have a basicly accordant trend,which shows the feasibility of applying CFD to evaluation in diesel intake port; provides detailed flow field information of the port,on the basis of which make a proposal of port improvement;after the modification of the intake port following the proposal,simulates the intake port three-dimensionally again,which shows the validity of applying CFD to improve diesel intake port.The author applies the flow field results to guide the port modification and achieves the purpose of taking effect quickly and lowering cost during development.

关 键 词： 螺旋进气道 计算流体力学 稳流试验 流量系数 涡流比 数值模拟 柴油机

领　　域： [动力工程及工程热物理]