The Effect of Nonlinear Drag on the Motion and Settling Velocity of Heavy Particles
The Effect of Nonlinear Drag on the Motion and Settling Velocity of Heavy Particles
复制标题
非线性阻力对重颗粒运动和沉降速度的影响
DOI：
10.1175/1520-0469(1995)052
复制
发表时间：
1995
影响因子：
3.1
通讯作者：
E. Genikhovich
中科院分区：
文献类型：
--
作者：
J. Stout;S. Arya;E. Genikhovich
研究了湍流大气中非线性阻力对重粒子运动和沉降速度的影响。作者比较系统地处理这个问题，首先考虑粒子对更简单的流体运动的响应，这些运动是更复杂的湍流场的子过程。作者首先考虑了静止流体中重力作用下粒子的运动和时间响应。然后研究了下落粒子与其周围流体之间相对速度的突然阵风或阶跃变化的影响。作者论证了突然阵风产生的水平相对运动倾向于降低穗的沉降速度。在简单振荡流体中，沉降速度的减小量随着流体振荡振幅的增大而增大。作者还探讨了振动频率对沉降速度的影响，并表明如果流体振动周期小于颗粒响应周期，则沉降速度将会降低。
Abstract The effects of nonlinear drag on the motion and settling velocity of heavy particles in a turbulent atmosphere are investigated. The authors approach the problem rather systematically by first considering the response of particles to much simpler fluid motions that are subprocesses of the more complex turbulent field. The authors first consider the motion and time response of particles falling under gravity in still fluid. Then the effects of a sudden gust or step change in relative velocity between a falling particle and its surrounding fluid are investigated. The authors demonstrate that horizontal relative motion produced by a sudden gust tends to reduce the settling velocity of a panicle. In simple oscillating fluids it is shown that the reduction of settling velocity increases with increasing amplitude of fluid oscillation. The authors also explore the effects of oscillation frequency on the settling velocity and show that if the period of fluid oscillation is less than the particle response...