柴油机缸内燃油分布特性

应用商用CFD模拟软件FIRE针对YD4A75-C3电控共轨柴油机实际工作过程中的燃油分布特性进行了深入研究。结果表明:燃油喷入缸内后迅速发生雾化,形成燃油蒸汽,其在射流动能的推动下向燃烧室壁面、凹坑及余隙内进行扩散。燃油在运动过程中,缸内燃油分布区域较为集中,分布的空间体积较小,燃油浓度分布存在严重的不均匀性,基本以高浓形态存在于缸内。同时,未燃燃油吸收了较多燃烧过程所释放的热量,燃烧前已具有较高的基础温度,进一步促进了局部高温区域的产生及有害排放物的生成。

Characteristics of fuel distribution in cylinder for diesel Engine

The characteristics of fuel distribution were further researched during the practice working process of YD4A75-C3 electronic-controlled common rail diesel engine by using commercial CFD software FIRE.The research results showed that fuel atomizes rapidly and forms mixture after injected into the cylinder,then the mixture is diffused to the combustion chamber wall,concave and clearance by jet kinetic energy.The fuel distribution is relatively concentrated,and the spatial distribution volume is relatively small,so the fuel concentration is very unevenly distributed and basically exists in the form of high concentration.Meanwhile,unburned fuel absorbs quantity of heat released by the combustion process so the ambient temperature is much higher before combustion,which further promotes the producing of high temperature zones and emissions.