【摘要】 运用CFD软件对直喷柴油机燃烧室中的喷雾及燃烧过程进行数值计算,考察了不同喷雾夹角下燃油的雾化过程、射流的发展形态以及近壁面区域浓度场的分布情况,并将计算结果进行了对比分析。结果表明,高速的射流漩涡对混合气的卷吸能力很强,油束末端的滞止区呈现较高的浓度;喷雾夹角过大会使燃油喷溅到燃烧室壁上,过小则活塞顶隙内的空气利用不充分,均对燃烧过程造成不良影响。更多还原

【Abstract】 In this paper,the CFD software was used in numerical simulation of fuel spray and combustion in chamber of DI diesel engine.Under different spray angles,the atomization of fuel and wall jet evolution were simulated numerically.The distribution of concentration fields nearby the wall also was studied for several situations.And the results between different situations were compared and analyzed.Results show that high speed wall jet vortex absorbs strongly mixture nearby.The concentration in stagnant area of spray bottom is higher than the others.The fuel spray will be injected on the wall of chamber with a bigger spray angle,but with a less one the air of piston head will not be used fully.All of which will influence the fuel combustion badly.更多还原