Laser Doppler velocimetry measurements of particle velocity fluctuations in a concentrated suspension
Laser Doppler velocimetry measurements of particle velocity fluctuations in a concentrated suspension
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激光多普勒测速法测量浓缩悬浮液中的颗粒速度波动
DOI：
10.1122/1.1427908
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发表时间：
2002
影响因子：
3.3
通讯作者：
Robert A. Brown
中科院分区：
文献类型：
--
作者：
N. Shapley;R. Armstrong;Robert A. Brown
最近的统计本构模型的悬浮液中的中性浮力，非胶体，固体球在牛顿流体表明，颗粒迁移响应梯度的“悬浮温度”，定义为平均动能中包含的颗粒速度波动。这些模型尚未与实验数据进行系统的比较。此外，“温度”模型假定各向同性的颗粒速度波动，因为悬浮液温度是作为标量给出的。然而，高度各向异性的粒子速度波动已被实验观察到，这表明悬浮温度张量是更现实的。我们使用激光多普勒测速仪测量颗粒间碰撞所产生的颗粒速度波动，在一个集中的悬浮液在近均匀的剪切流在一个狭窄的间隙同心圆柱Couette设备。我们比较了脉动速度分量的相对大小，并确定了每个分量的变化。
Recent statistical constitutive models of suspensions of neutrally buoyant, noncolloidal, solid spheres in Newtonian fluids suggest that the particles migrate in response to gradients in “suspension temperature,” defined as the average kinetic energy contained in the particle velocity fluctuations. These models have not yet been compared systematically with experimental data. In addition the “temperature'’ models assume isotropic particle velocity fluctuations, since the suspension temperature is given as a scalar. However, highly anisotropic particle velocity fluctuations have been observed experimentally, which suggests that a suspension temperature tensor is more realistic. We use laser Doppler velocimetry to measure particle velocity fluctuations arising from interparticle collisions in a concentrated suspension under nearly homogeneous shear flow in a narrow-gap concentric cylinder Couette device. We compare the relative sizes of the fluctuating velocity components and determine the variation of each...