Effect of Particle Residence Time on Particle Dispersion in a Plane Mixing Layer
Effect of Particle Residence Time on Particle Dispersion in a Plane Mixing Layer
复制标题
颗粒停留时间对平面混合层中颗粒分散的影响
DOI：
10.1115/1.2910208
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发表时间：
1993
影响因子：
2
通讯作者：
M. Maeda
中科院分区：
文献类型：
--
作者：
T. Ishima;K. Hishida;M. Maeda
为了研究颗粒停留时间对颗粒分散的影响，在气固两相相对速度较大的二维混合层中对颗粒分散进行了实验研究。将直径分别为42、72和135µm的球形玻璃颗粒直接加载到剪切层的起始处。用改进的两相流信号处理激光多普勒测速仪测量了颗粒数密度和颗粒和气相的速度。结果表明，由于驻留时间较短，相干涡旋的特征时间尺度明显变得相当于较短的特征时间尺度。颗粒弥散系数与扩展的斯托克斯数有很好的相关性，扩展的斯托克斯数定义为颗粒弛豫时间与考虑颗粒停留时间的实质涡流特征时间尺度的比值。
A particle dispersion has been experimentally investigated in a two-dimensional mixing layer with a large relative velocity between particle and gas-phase in order to clarify the effect of particle residence time on particle dispersion. Spherical glass particles 42, 72, and 135 {mu}m in diameter were loaded directly into the origin of the shear layer. Particle number density and the velocities of both particle and gas phase were measured by a laser Doppler velocimeter with modified signal processing for two-phase flow. The results confirmed that the characteristic time scale of the coherent eddy apparently became equivalent to a shorter characteristic time scale due to a less residence time. The particle dispersion coefficients were well correlated to the extended Stokes number defined as the ratio of the particle relaxation time to the substantial eddy characteristic time scale which was evaluated by taking account of the particle residence time.