柴油机缸内气体流动过程的数值计算

Numerical simulation of air flow in diesel chamber

在柴油机纯压缩工况下 ,用 KIVA— 程序对不同几何形状燃烧室气流的运动进行数值计算 .计算结果表明 ,燃烧室形状对缸内气体的运动有重要影响 .中央突起缩口燃烧室和缩口 ω燃烧室具有较高的涡流和挤流强度 ,并有较长的高涡流持续期 .

The air motion in different geometrical chamber is calculated using KIVA-Ⅱ program under the condition of compress process. The results show that the geometry of chamber plays an important role in in cylinder air flow. Two kinds of chamber shape, the contracted throat with central protrusion and contracted throat ω type, have high intensity and long duration of turbulence and squish movement. The diffuse combustion during the later period of combustion process could be enhanced by this kind of air flow and low emission could be achieved by retardation of fuel injection.