【作者】 李丹；

【导师】 刘德新；

【作者基本信息】 天津大学 ， 动力机械及工程， 2006， 硕士

【摘要】 塑料进气歧管可比铝进气歧管重量减轻50%以上,发动机动力性得到5～10%的提升,经济性和排放性也有相当改善,材料和制造成本都可得到降低。但是塑料进气歧管作为发动机进气系统最关键的零部件,其设计和制造难度很大。本文主要研究汽油机塑料进气歧管型腔的设计方法。首先分析了汽油机塑料进气歧管的结构功能及各附件的设计要求,研究了管内气流运动的波动效应和能量损失,提出了汽油机塑料进气歧管型腔的总体设计思路。研究了内燃机进气过程中一维非定常流动的数值解法。利用一维发动机工作过程仿真软件BOOST,建立了三种不同型号的发动机计算模型,以稳压腔容积,歧管长度、直径作为进气歧管设计过程中的目标优化函数,通过研究各参数对发动机性能的影响,提出设计原则,为进气歧管型腔设计提供基本参数。借助计算流体力学(CFD)辅助内燃机设计理论,研究了CFD在进气歧管开发中的应用及其模拟精度。利用三维流体计算软件FIRE对所设计的两款塑料进气歧管型腔进行流场模拟,深入研究了型腔内部流场分布和局部压力损失,为型腔的三维结构优化提供理论依据。对所设计的两款塑料进气歧管制作快速原型样件,分别对其进行发动机装配试验和台架试验。试验结果表明:用该方法设计的塑料进气歧管安装工艺合理,性能符合要求。本文采用虚拟设计理论,利用现代化集成设计方法,试验与模拟并行,加快了产品开发周期,降低了开发成本,可以高质量的完成设计任务。该方法既可用于指导进气系统的性能改进,还有利于加快国内塑料进气歧管的应用和推广。更多还原

【Abstract】 Plastic air intake manifolds are successfully replacing aluminum air intake manifolds. Good performance, lower weight and costs are the main reasons behind this trend. But the manifold has an intricate shape owing to its performance and layout requirements, so it is difficult to design and produce. To bring the plastic manifold into practical use in China, this paper mainly researches the design method of plastic air intake manifold cavity for gasoline engine.Firstly,the configuration function of plastic air intake manifold for gasoline engine was analyzed, and the design requirement of each accessory was proposed. Then the wave resonance and the energy loss of intake manifold were researched in detail, which are important to manifold design. On the base, the way of design plastic air intake manifold cavity was put forward.After studying the numerical simulation of unsteady flow in intake manifold, 3 different gasoline engine models were set up using simulation software AVL-BOOST. Through one-dimensional engine cycle and gas exchange simulation, the influence of the plenum volume, manifold length and diameter on engine performance were found out. Then the principle of the cavity design was proposed, which can provide the fundamental structure parameters for intake manifold cavity design.The theory of CFD assisted in engine development was studied. And the mesh structure was also researched which was the key point to compute precision. The three-dimensional numerical simulation of air flows in two plastic air intake manifolds of gasoline engine was performed using CFD software FIRE. The simulated flow field provided a detailed insight into the three-dimensional air flow under different conditions. The calculation results of manifolds flow performance can provide theoretical directions for intake manifold cavity design.The two plastic intake manifold cavities mold designed with 3D designing software were used to make original samples quickly in the rapid prototype center. The engine test development was finished with these samples, including flow performance assessment, assembly checkout and engine testing. Finally, the testing results showed that this method was reasonable and correct.The design method of plastic air intake manifold for gasoline engine proposed in更多还原