【作者】 韩义勇；

【导师】 罗光缉；

【作者基本信息】 广西大学 ， 动力机械及工程， 2005， 硕士

【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;采用逆向工程的方法建立了YCF3200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CFD数值模拟;首次给出了气道CFD数值模拟中判定计算结束的原则;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;依气道改进建议修磨了缸盖,并进行了稳流试验,试验结果与预期的目标吻合良好,验证了应用CFD改进气道的正确性。本文首次将流场分析结果直接应用于指导气道修磨,达到见效快、降低开发成本的良好效果。更多还原

【Abstract】 The structure of intake port directly affects the quantity of fresh air and the strength of swirl in cylinder, which have relations with mixture forming, so affects the combustion, exhaust and total performance. Based on experiential design and steady flow test, the traditional port design method needs a long developing period, moreover is hard to get the ideal scheme. Using 3D numerical simulation, the reserch on intake port could acquire not only the integration parameters, but also microcosmic information of the flow field in abundance, which provides important basis to improve and design the intake port optimizingly.In this dissertation, the author summarizes the development and research on diesel intake port; selects the mathematici and numerical models of flow in port; simulates the helical intake port of YCF3200 three-dimensionally in CFD software AVL FIRE, by upbuilding the geometric model via reverse engineering and using the results of steady flow test rig as boundary conditions; gives the rule how to judge the endof calculation in CFD simulation of port for the first time; validates the calculational results via the Ricado 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 table a proposal of port improvement; after the modification on the cylinder head following the proposal, tests it on the steady flow test rig and the results accord with forecast, which farther shows the validity of applying CFD to improving diesel intake port. The author for the first time applies the flow field results to guide the port modification and achieves the purpose of taking effect quickly and lowering cost during development.更多还原