The Gravity Effects on the Collision Frequency of Monodisperse Particles in Turbulent Flows
The Gravity Effects on the Collision Frequency of Monodisperse Particles in Turbulent Flows
复制标题
重力对湍流中单分散粒子碰撞频率的影响
DOI：
10.1299/kikaib.71.1225
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
S. Komori
中科院分区：
文献类型：
--
作者：
R. Onishi;S. Komori
湍流中单分散粒子的碰撞问题在机械工程和云微物理研究中都具有重要意义。许多研究调查的现象，但他们忽略了重力的影响，以使用简单的假设各向同性粒子运动的粒子上。因此，在这项研究中，我们研究了重力的碰撞频率的影响，通过使用直接的数值模拟。结果表明，如果忽略重力的影响，碰撞频率变高。研究还发现，当颗粒终端速度与流体速度脉动均方根值相当或大于流体速度脉动均方根值时，重力效应是显著的。
Collisions of monodisperse particles in turbulent flows are important both in the mechanical engineering and in the cloud microphysics. A number of studies investigated the phenomena but they neglected the gravity effects acting on the particles in order to use simple assumption of isotropic particle motions. In this study, therefore, we investigated the gravity effects on the collision frequency by using a direct numerical simulation. The results show that if the gravity effects are neglected, collision frequency becomes higher. It is also found that the gravity effects are significant when the particle terminal velocity is comparable to or greater than the root mean square value of fluid velocity fluctuation.