柴油液滴撞击倾斜壁面碰撞速度效应数值分析

发布时间：2018-12-13 18:25

【摘要】：采用复合水平集和流体体积法并综合考虑传热及接触热阻的作用建立了液滴碰撞倾斜壁面的数值模型,并验证了模型的可靠性。通过分析计算,获得了柴油液滴撞壁动力学形态的变化规律,揭示了液滴撞壁流动破碎机理,探索了液滴前、后铺展系数和铺展速度、总铺展系数以及壁面平均热流密度的碰撞速度效应规律。研究表明:液滴碰撞倾斜壁面射流和飞溅特征仅出现在前铺展边缘,且射流存在颈部破碎和根部破碎;液滴前铺展边缘射流区域内压力梯度是射流形成、发展及其颈部、根部断裂的主要原因;毛细波的作用是射流颈部和根部破碎的关键因素;碰撞速度越大,液滴的前、后铺展系数和铺展速度、总铺展系数以及壁面平均热流密度均越大;随着碰撞速度的增加,液滴撞壁特性的碰撞速度效应逐渐减小。
[Abstract]:The numerical model of liquid droplet collision slanting wall is established by using the composite horizontal set and fluid volume method and considering the effects of heat transfer and contact thermal resistance, and the reliability of the model is verified. Through the analysis and calculation, the change law of the dynamic form of the diesel droplet impact wall is obtained, the mechanism of the droplet impinging wall flow is revealed, and the spreading coefficient and spreading speed before and after the droplet are explored. The impact velocity effect of the total spreading coefficient and the average heat flux on the wall. The results show that the jet and spattering characteristics of droplet impact inclined wall appear only at the front spreading edge, and the jet has neck and root breakage. The pressure gradient is the main cause of jet formation, development, neck and root fracture, and capillary wave is the key factor of jet neck and root breakage. The larger the impact velocity, the greater the spreading coefficient and spreading velocity, the greater the total spreading coefficient and the average heat flux of the wall, and the less the impact velocity effect of the droplet impact on the wall with the increase of the impact velocity.
【作者单位】：中国石油大学(华东)化学工程学院;中海油研究总院;合肥工业大学机械与汽车工程学院;萨里大学工程与物理科学学院;
【基金】：“十二五”国家科技支撑计划项目(2012BAD30B01) 中央高校基本科研业务费专项资金项目(15CX06052A)
【分类号】：O35

【相似文献】