缸内高压直喷柴油/天然气喷射混合过程分析

Research of In-cylinder High Pressure Direct Injection and Mixture of Diesel and Natural Gas

在天然气发动机中,天然气和柴油射流的喷射及混合过程对燃烧排放性能有重要影响。本文基于AVL FIRE软件,模拟了定容燃烧腔内高压天然气和柴油射流喷射过程,分析了不同喷孔高度、喷孔倾斜角以及喷孔交角下柴油和天然气射流的混合情况,研究结果表明喷孔高度,倾斜角,交角与喷雾贯穿距呈正比,柴油喷雾贯穿距是影响雾化质量的重要因素。喷孔相对位置中喷孔交角因素对射流的影响最大,对柴油喷雾的雾化效果提升明显。

In the natural gas engine,the injection and mixture of natural gas and diesel jets have much effect on the combustion and emission performance.AVL-FIRE software is used in this paper to simulate the process in the constant chamber.Different nozzle height,inclination angle and crossing angle are analyzed.The result shows that the larger the nozzle height,inclination angle and crossing angle,the larger the diesel penetration,the diesel penetration is the key point to the atomization.The crossing angle has most important influence on the jet characteristics.