余波,邓晰文,雷基林,等.振荡条件下金属颗粒对气液两相流动与混合特性影响的试验研究[J].内燃机工程,2024,45(2):93-101.
振荡条件下金属颗粒对气液两相流动与混合特性影响的试验研究
Experimental Study of the Effects of Metal Particles on the Flow and Mixing Characteristics of Gas–Liquid Two-Phase Under Oscillation Conditions
DOI：10.13949/j.cnki.nrjgc.2024.02.011
关键词:活塞  内冷油腔  气液两相流  可视化  金属颗粒
Key Words:piston  cooling gallery  gas–liquid two-phase flow  visualization  metal particle
基金项目:云南省科技计划项目（202302AC08002，202202AB080011）；云南省基础研究计划项目（202101BE010001-059，202101AT070266）
作者单位E-mail
余波 昆明理工大学 云南省内燃机重点实验室，昆明 650500 1668274946@qq.com 
邓晰文* 昆明理工大学 云南省内燃机重点实验室，昆明 650500 xixiwen@126.com 
雷基林 昆明理工大学 云南省内燃机重点实验室，昆明 650500 leijilin@sina.com 
肖杰 昆明理工大学 云南省内燃机重点实验室，昆明 650500 2210784080@qq.com 
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摘要:为进一步提升柴油机活塞腔的换热性能，通过加入金属颗粒来提升振荡状态下的两相混合程度。采用振荡流动试验方法，结合数字图像处理技术，研究金属颗粒在振荡状态下的运动学特性和两相振荡流动特性，进一步讨论转速、充液率对金属颗粒运动和最大气泡直径和混合率的影响。结果表明：转速是影响气液两相流振荡流动效果的主要因素。随着转速的增加，金属颗粒到达方腔上壁面时间缩短，瞬时速度增大，相对于270 r/min，330 r/min冲击上壁面的平均速度变化率增加133%，冲击壁面的强度增加。相对于25%充液率，75%充液率的金属颗粒冲击上壁面的最大瞬时速度降低68%，充液率过高，降低颗粒冲击上壁面强度。50%充液率左右和高转速条件下，颗粒冲击壁面强度降低，但气液两相流混合程度最好。
Abstract:To further improve the heat transfer performance of the cooling gallery of diesel engine pistons， metal particles introduced to enhance the degree of two-phase mixing under oscillation conditions. By using the oscillating flow experimental method and combining it with digital image processing techniques， the kinematic characteristics of metal particles under oscillation conditions and the characteristics of two-phase oscillating flow were studied. The effects of rotational speeds and filling ratios on the motion of metal particles， as well as the maximum bubble diameters and mixing rates， were further discussed. The results show that rotational speed is the main factor affecting the oscillating flow effects of gas–liquid two-phase flow. With the increase of rotational speeds， the time for metal particles to reach the upper wall of the cooling gallery is shortened， resulting in an increase in instantaneous velocities. Compared to 270 r/min， the average velocity change rate of metal particles impacting the top wall increases by 133% at 330 r/min， indicating an increase in the intensity of wall impact. Compared to the filling ratio of 25%， the maximum instantaneous velocity of metal particles impacting the top wall is reduced by 68% at the filling ratio of 75%， indicating a decrease in the intensity of wall impact at high filling ratios. At filling ratios around 50% and under high rotational speed conditions， the intensity of particle impact on the wall is reduced， but the degree of gas-liquid two-phase mixing is the best.
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