非球形粒子反弹分布特性试验探究

Experimental Research on Rebound Distribution Characteristics of Non-Spherical Particles

关键词:  粒子-壁面碰撞  分布特性  恢复系数  非球形粒子

Key words:  Particle-wall collision  Distribution characteristics  Restitution coefficient  Non-spherical particle

摘要:

砂粒撞击发动机进气粒子分离器壁面会决定粒子的运动轨迹。为了获得不规则形状对反弹特性的影响，进行了600[μm]钢珠及600 ~ 800[μm]非球形石英颗粒撞击树脂涂层板/合金钢板/铝板的试验，并分析了统计分布规律。试验结果表明，球形颗粒的恢复系数较为集中，而非球形的石英粒子在相同角度下的恢复系数大致符合高斯分布。切向恢复系数分布则随着撞击角度增加变得更加集中，标准差在撞击角为10°时可达0.28。法向恢复系数趋势相反，标准差在70°时为0.38。法向恢复系数小于0的概率为0，且呈正偏态分布。不同材料壁面的恢复系数相对分布范围主要受粗糙度影响，但对于法向恢复系数，还受到法向分量引起的变形的影响。

Abstract:

Sand impinging engine inlet particle separator wall will determine the particle trajectories. To get the influence of irregular shape on the rebound characteristics， the experiment of 600[μm] steel ball and 600~800[μm] non-spherical quartz particles impinging resin coated/alloy steel/Al plate was carried， and the statistical distribution law was analyzed. The experimental results show that the restitution coefficient of spherical particles is more concentrated， while the restitution coefficient of non-spherical quartz particles in the same angle accords with Gaussian distribution. The tangential restitution coefficient becomes more concentrated with the increase of the impact angle， while its standard deviation can be up to 0.28 at[θi=10°]. The normal restitution coefficient shows an opposite trend， while its standard deviation can be up to 0.38 at[θi=70°]. The normal restitution coefficient is positively skew distribution， and it won’t be less than 0. The relative distribution range of restitution coefficient impacting different surface is mainly affected by roughness. But for normal restitution coefficient， the deformation caused by the normal impact is also of great importance.