天然气发动机缸内燃烧过程的三维数值模拟.docVIP

 PAGE 46 天然气发动机缸内燃烧过程的三维数值模拟 摘要 随着油价的日益上涨，能源问题在我们的切身生活当中日益凸显。如今，天然气作为发动机燃料应用的研究已发展到一定规模，这一类的研究也受到越来越多的关注。本研究旨在对天然气发动机的燃烧过程进行进一步研究，对CNG发动机的设计开发提供一定的指导，同时对天然气的缸内燃烧研究也具有相当的价值。 本研究从三维数值模拟计算模型和数值计算方法出发，结合缸内气体的湍流流动模型、燃烧模型和排放模型的理论分析，根据天然气发动机的工作特性，选取合适的计算模型和方法，建立了模拟发动机进气流动、缸内燃烧、排气过程的三维动态网格，模拟计算了完整的工作循环过程，得出发动机在不同曲轴转角下的缸内的流动和燃烧情况，并将模拟结果和试验进行对比，为工作性能的进一步改进优化提供理论依据。 关键词：天然气发动机 燃烧 三维建模 三维数值计算 3-D Numerical Simulation for the Combustion Process of the CNG Engine Abstract With increasing price of oil, the energy problem has been more and more serious in our daily life. At present, the research of natural gas used as a kind of engine fuel has come to a new level, and this kind of research is getting more and more attention. This paper aims at studying the combustion process in CNG engine for a further step, providing some instruction on CNG engine design, and benefiting the study on natural gas combustion in cylinder as well. In this paper, based on three-dimensional numerical simulation model and numerical method, analyze the turbulent flow, combustion model and emission model located in cylinder, considering the natural gas engine operating characteristics, select appropriate models and methods of calculation, the three-dimensional dynamic mesh was built to simulate the process of the intake flow, cylinder combustion and exhaust, and the simulation calculation was done. so as to conclude the flow and the combustion status under different crank angle, compared the simulation results and testing results to identify the deficiencies in the process of natural gas engine, to provide the theoretical basis for engine optimization. Key words: Natural Gas Engine Combustion Three-Dimensional model Three-Dimensional Numerical calculation 目 录  TOC \o 1-2 \h \z \u   HYPERLINK \l _Toc264042582 摘要  PAGEREF _Toc264042582 \h I  HYPERLINK \l _Toc264042583 Abstract  PAGEREF _Toc264042583 \h II  HYPERLINK \l _Toc264042584 一、绪论  PAGEREF _Toc264042584 \