首页|双喷油器大角度喷雾碰撞模拟与试验研究

双喷油器大角度喷雾碰撞模拟与试验研究

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为提高柴油机升功率,高功率密度(HPD)柴油机采用双喷油器.但在高温环境(1200 K)下,过多的燃油量不仅增加了燃烧当量比,而且缩短了滞燃期,使燃油未充分雾化就开始着火,从而导致燃烧恶化现象.组织喷雾碰撞能一定程度上促进油气混合、缓解燃烧恶化,目前碰撞喷雾相关研究中喷雾的碰撞角度较小,且主要针对喷雾雾化.为进一步提高超高功率密度柴油机的燃烧效率,本文基于可视化定容燃烧弹(CVCC)探究了双喷油器大角度碰撞喷雾(90°、120°、150°、180°)的雾化和碳烟生成特性,并利用 Star-ccm+软件对喷雾碰撞进行了模拟.研究发现,任意角度喷雾碰撞的动能损失均可以通过 180°对撞喷雾的动能损失预测,并基于此提出喷雾碰撞的动能损失模型.实验表明,随碰撞角度增加,碰撞后喷雾区域湍动能增强,雾化改善,燃烧品质提升,碳烟峰值减小,碳烟氧化速度加快.
Simulation and Experimental Study of Large-Angle Spray Collision of Double Injectors
In order to increase the liter power of the diesel engine,High Power Density(HPD)diesel engine adopts dual fuel injectors.However,in a high-temperature environment(1200 K),the excessive amount of fuel not only increases the combustion equivalent ratio but also shortens the lag period,so that the fuel begins to ignite before it is fully atomized,resulting in combustion deterioration.Organizing spray collision can promote oil-gas mixing and alleviate the deterioration of combustion to a certain extent.The current research on collision spray is characterized by small collision angle and mainly aimed at spray atomization.In order to further improve the com-bustion efficiency of ultra-high power density diesel engine,the atomization and soot generation characteristics of large-angle collision spray(90°,120°,150°,180°)of dual injectors were explored based on the visual constant volume combustion bomb,and the spray collision was simulated by Star-ccm+software.It was found that the ki-netic energy loss of spray collision at any angle can be predicted by the kinetic energy loss of 180° collision spray,based on which a kinetic energy loss model of spray collision is proposed.The experimental results show that with the increase of collision angle,the turbulent kinetic energy of the spray area increases,both the atomization and the combustion quality are improved,the peak value of soot decreases,and the oxidation rate of soot accelerates after the collision.

spray impingementhigh-temperature conditionturbulence kinetic energykinetic energy loss modelconstant volume combustion chamber

李晓捷、王兆文、胡谊、王亮、汪安稳、成晓北

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华中科技大学能源与动力工程学院,武汉 430074

喷雾碰撞 高温环境 湍动能 动能损失模型 定容燃烧弹

2025

燃烧科学与技术
天津大学

燃烧科学与技术

北大核心
影响因子:0.617
ISSN:1006-8740
年,卷(期):2025.31(1)