Flow patterns of solids in a two-dimensional spouted bed with draft plates: PIV measurement and DEM simulations
Flow patterns of solids in a two-dimensional spouted bed with draft plates: PIV measurement and DEM simulations
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DOI：
10.1016/j.powtec.2007.11.021
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发表时间：
2008-03
影响因子：
5.2
通讯作者：
X.-L. Zhao;Shuiqing Li;G.-Q. Liu;Q. Song;Q. Yao
中科院分区：
文献类型：
--
作者：
X.-L. Zhao;Shuiqing Li;G.-Q. Liu;Q. Song;Q. Yao
采用颗粒图像测速（PIV）和离散元法与流体力学计算（DEM-CFD）相结合的方法，研究了带导流板的二维喷流床（2DSB）内颗粒的流动特性，同时考虑了气体湍流效应。该床由一个宽152毫米、深15毫米的矩形柱、一个含60°角的圆锥形部分和两个间距为15毫米的吃水板组成。采用高速CCD相机记录颗粒流图像，采用自主开发的PIV算法进行分析，得到时间平均颗粒速度场。实验预测，加入导流板不仅使颗粒在环空中的流线更陡，而且使速度量级更小。DEM结果较好地预测了颗粒垂直速度沿床层中心线的纵剖面，特别是在喷口下部快速加速阶段。最后，本文引入阻力和净力的分布来解释PIV测量的粒子速度分布。
Particle flow behaviors in a two-dimensional spouted bed (2DSB) with draft plates were studied using both the particle image velocimetry (PIV) and the combined technique of discrete element method and fluid dynamic computation (DEM-CFD) while considering the gas turbulence effect. The bed consisted of a rectangular column, 152 mm wide and 15 mm deep, a conical section with an included 60° angle and two draft plates with a distance of 15 mm. Images of particle flow were recorded by a high speed CCD camera and analyzed using a self-developed PIV algorithm to obtain a time-averaged particle velocity field. Experiments predict that the addition of draft plates not only makes the streamline of particles in the annulus steeper, but the velocity magnitude is made smaller as well. DEM results predict well the longitudinal profile of the particle vertical velocity along the bed centerline, especially during the rapid acceleration stage at the lower part of the spout. Finally, the distributions of drag forces and net forces are introduced in this paper to explain the particle velocity profiles by PIV measurement.