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Development of General-Purpose Computer Programs to Predict the Performance of Four-Cycle Internal Combustion Engines for Improving Their Thermal Efficiency

开发通用计算机程序来预测四冲程内燃机的性能以提高其热效率

基本信息

批准号：
05555066
负责人：
SHIMAMOTO Yuzuru
金额：
$ 6.08万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

A simulation program has been developed to predict the engine performance, achieving little numerical diffusion by the use of teh characteristic method with two mesh series. The dimension effect of the intake system on the EGR rate has been estimated for a four-cylinder engine. The availability of the program is recognized by the good agreement between the calculated and experimental results. A scheme to calculate the shock wave in pipes has been fundamentally investigated. A new procedure to perform characteristics has been developed and found to provide accurate and efficient evaluations of gas flows in pipes including the gas flow in a tapered pipe or gas flow with numerical diffusion. The flow characteristics of the turbine and the compressor used in compound power systems have been expressed as function forms containing several parameters. These enable us to evaluate the performance of compound power systems with their various configurations.In three-dimensional analysis of the pressure wave and the gas flow in intake and exhaust systems, the CIP method has been improved by applying the general curvilinear coordinate transformation in order to calculate the gas flow and pressure wave in arbitrarily-shaped passages such as silencers. The effect of the configuration of silencers on the attenuating characteristics and the pressure losses has been made clear by examining the calculated results. For numerically analyzing three-dimensional gas flows in engine intake ports and combustion chambers, a calculation method (GTT) which can deal with engine models having complicated shapes by using body-fitted grids has been developed. The forming and collapsing processes of tumbling vortices have been made clear using the GTT program. By incorporating fuel spray models into this program, the behavior of fuel droplets and the distribution of fuel vapor concentration in liquid fuel injection engines have been predicted.

开发了用于发动机性能预测的模拟程序，采用双网格系列的特征线法，数值扩散很小。在一台四缸发动机上，估算了进气系统尺寸对废气再循环率的影响。计算结果与实验结果吻合较好，验证了程序的有效性。从根本上研究了一种计算管道中冲击波的方案。发展了一种新的特征分析方法，可以准确、有效地评价管道中的气体流动，包括锥形管道中的气体流动或数值扩散的气体流动。复合电力系统中涡轮和压气机的流动特性被表示为包含多个参数的函数形式。在进排气系统压力波和气体流动的三维分析中，通过应用广义曲线坐标变换对CIP方法进行了改进，以计算消声器等任意形状通道中的气体流动和压力波。通过对计算结果的检验，明确了消声器的结构对消声特性和压力损失的影响。为了数值分析发动机进气道和燃烧室的三维气体流动，提出了一种采用贴体网格处理复杂形状发动机模型的计算方法(GTT)。利用GTT程序对滚动涡的形成和崩塌过程进行了数值模拟。通过将燃油喷雾模型融入到该程序中，预测了液体燃油喷射发动机中燃油液滴的行为和燃油蒸汽浓度的分布。