I燃烧过程数值模拟及研究.pdf

论文分类号 TK39 单位代码 10183 密级内部研究生学号 2001422068 I发动机燃烧过程数值模拟及研究Numerical Simulation and Study of Fuelled Ethanol HCCI bustion 作者姓名:尚海军专业:热能工程导师姓名及职称:许思传教授论文起止年月:I燃烧进程主要受控于混合气的化学反应动力学。I发动机燃烧过程,本文利用美国Lawrence Livernore 国家实验室公布的乙醇燃烧复杂化学动力学机理和热力学数据,I燃烧模型。在燃烧过程中乙醇是通过分解和脱氢两条途径消耗的,其燃烧是由57种组分参与、383个基元反应组成的复杂反应过程。本文采用了能够自动调节步长的Gear算法求解复杂化学反应动力学问题,在计算速度和计算精度上得到了很好的效果。该模型是以传统的零维模型为基础建立的,因此继承了传统零维模型气缸内各点状态相同的特点,I燃烧特性和排放特性。运用建立的燃烧模型,分析了压缩比、进气温度、进气压力、当量比、I燃烧的影响,以及各组分变化的过程,发现压缩比、进气温度、I燃烧过程,有非常显著的影响。关键词:HCCI,Gear算法,EGR,化学反应动力学,刚性方程组,数值模拟吉林大学硕士学位论文Abstract Homogenous pression Ignition (HCCI) combustion is a process dominated by chemical ics of the fuel-air mixture. To investigate characteristics of ethanol HCCI engine, this paper created a detailed chemical ics bustion model using mechanisms and thermal data publicized by America Lawrence Livernore National Lab. There are two ways to consume ethanol—position reaction and dehydrogenation reaction. The chemical ics mechanism for ethanol consists of 57 species and 383 elementary reactions. The paper used Gear BDF method to solve the stiff difference equations. GearBDF can control steps automatically to keep enough precision. Results showed good encouragements both step and precision. The new model is based on the conventional single-zone, so it has same characteristics as conventional model. Also the new bustion model can bustion and emission. Used bustion model, the paper discussed influences of some factors pression ratio, intake temperature, intake pressure, equivalence ratio, engine speed and EGR. The result showed pression ratio, intake temperature, equivalence ratio and EGR have prominent effect. Key words:HCCI, Gear method, EGR,Chemical ics, Stiff difference equations 吉林大学硕士学位论文- I - 目录第一章绪论........................................................................................................ 1 引言..................................................... 1 HCCI发动机研究现状..................................