【作者】 王卫华；

【导师】 钱作勤；

【作者基本信息】 武汉理工大学 ， 轮机工程， 2006， 硕士

【摘要】 随着70年代能源危机的爆发,人们越来越重视发动机的经济性,而随着各国环保意识的日益增强,为了减少大气污染,发动机的排放性能获得越来越高的重视。由于四气门柴油机具有优越的动力性、经济性和排放性能,应而获得了广泛的应用。本文以4112四气门柴油机进排气系统中的进气道为主要研究对象,研究了该柴油机两进气道进气过程及缸内气体流动状况。本文对4112四气门柴油机进气道进行了实验研究和数值仿真。 本文首先根据逆向工程,利用三坐标测量机得到气道模型的点云图,使用三维工程设计软件Pro/Engineer建立了柴油机气道的三维实体模型。随着计算机技术的发展,计算流体动力学现已成为解决各种流体流动与传热问题的强有力工具,具有设计成本低、周期短的特点。本文用三维计算流体动力学软件AVL FIRE对该气道模型进行了不同气门升程情况下稳态流动的三维数值模拟计算,获得其内部的压力场、速度场等的详细分布,计算出各升程下的气体流量系数和涡流比,分析了双进气道在截面上的气流干涉情况,为气道设计和改进提供重要的理论依据。 气道稳流模拟试验是发动机产品开发和燃烧过程研究的重要组成部分,气道稳流模拟试验是用来模拟实际发动机的进气状况,评估发动机进排气系统的通流特性及进气道涡流形成能力,为发动机进排气系统的研究开发及燃烧过程研究提供重要的试验依据。本文对该4112四气门柴油机进行进气道定压差稳流实验,得到它各个不同升程(共5个升程)情况下的质量流量和动量矩流率,计算结果与实验结果基本吻合。结果表明,应用反向工程的方法获得气道三维实体模型是可行的,应用CFD软件做气道流动计算其精度是足够的。 最后,对全文工作进行了总结,指出了本文的一些不足之处,并对今后的研究工作进行展望。更多还原

【Abstract】 With the outburst of the energy crisis in the seventies, people paid attention to the economy of the engine more and more, and the enhancement of the environmental consciousness of various countries day by day, in order to reduce the air pollution, the discharge performance of the engine obtains higher and higher attention. Four valves diesel engine obtains the widespread application because of superior dynamical performance, the efficiency and discharge performance. The main research object of the thesis is inlet port of 4112 four valves diesel intake and exhaust system, it studies the intake process in the double ports of the four valves diesel and the flow status in cylinder. The research performs the experimental study and the numerical simulation to the four valves diesel engine air intake.First according to the reverse engineering, cloud of points chart of intake model is obtained by three coordinate measurement machine, three dimensional model of the diesel engine air intake is established by means of software Pro/Engineer. As the development of computer technology, the computational fluid dynamics has become a powerful tool to the problem of fluid flow and heat transfer, it is low-cost, short cycle. Carry on stable flow three dimensional numerical computation at different valve lift with three dimensional computation hydrodynamics software AVL FIRE, obtained the detailed distribution of the pressure field, the velocity field and so on, calculate flow coefficient and swirl ratio at different lift, analyze the air stream interference on double intake ports in cross-section. Provide the important theory basis for diesel intake design and improvement.Steady flow simulation test product development and combustion engine is an important part of combustion engine product development and combustion process research. Steady flow simulation test is used to simulate actual engine intake status, evaluate the capacity of air flow of combustion engine intake and exhaust system and the form capacity of swirl ratio, it provide important test basis for the research and development on engine intake and exhaust system and for combustion process study. Carry on steady flow test with steady pressure difference, obtains the mass flow andmomentum rate. The numerical computed result and the steady flow test result of intake port are basically tallies. The result indicated that it is feasible to obtain intake port three dimensional model by means of reverse engineering method. Taking the CFD software to intake flow calculates its precision is enough.Finally, make a summary, point out some shortage, make a expectation to the next research work.更多还原