Experiments were carried out to study the sedimentation of a two‐dimensional particle cloud. When a large number of particles (glass beads) of uniform size are released from a two‐dimensional opening into a column of fresh water, the mixture initially descends as a thermal; however, after some time, the particles start settling individually, thus leaving the parent fluid behind. For a given type of particle, the critical depth z_c at which this transition occurs, measured from a virtual origin, was found to change as z_cws/ν∼(Q/νw_s)^α, with α≂0.3, where w_s is the terminal velocity of a single particle, ν is the kinematic viscosity, and Q is the total buoyancy of the released particles per unit length. The descending velocity and the spatial growth of the particle cloud were found to depend on its sedimentation characteristics.

中文翻译：

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粒子云沉积模式的转变

实验进行了研究 沉降二维粒子云 当大量均匀大小的颗粒（玻璃珠）从二维开口释放到一列淡水中时，混合物开始以热态下降。但是，一段时间后，颗粒开始单独沉降，从而使母液留下来。对于给定类型的粒子，发生此转变的临界深度z _c被测从虚拟原点，被发现变化ž _CW小号/ν~（Q /ν瓦特_小号）^α，与α≂0.3，其中瓦特_小号是单个粒子的终端速度，ν是运动学的 粘度，和Q是每单位长度的释放的颗粒的总浮力。发现粒子云的下降速度和空间增长取决于其沉降 特征。