东华大学环境科学与工程学院, 上海 201620
School of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
基于离散相模型(DPM),模拟研究了不同横截面形状异形纤维在拦截和惯性碰撞2种机制下对颗粒物的捕集效率;考察了颗粒物粒径、入口风速、纤维填充率和纤维放置方式对不同横截面形状异形纤维捕集颗粒物效率的影响。结果表明,当颗粒物粒径为0.5~2.5 μm,入口风速为0.5 m·s
时,颗粒物粒径为2.5 μm时,异形纤维对颗粒物的捕集效率均随入口风速的增加而增加;当填充率为1.2%~4.0%时,颗粒物粒径为2.5 μm时,异形纤维对颗粒物的捕集效率随填充率的增加而增加,其中横截面为正三角形的纤维对颗粒物的捕集效率均最大。异形纤维的径向异形度相同时,纤维边垂线与来流方向平行的放置方式对颗粒物的捕集效率较高。不同横截面形状异形纤维的径向异形度系数越小,对颗粒物的捕集效率受纤维的放置方式的影响越小。本研究可为新型纤维滤料的开发提供参考。
The research was conducted to study the efficiency of particulate matter captured by shaped fibers with different cross-section, based on the discrete phase model(DPM). The capture efficiency of particulate matter was simulated in two trapping mechanisms of the interception and inertial impaction for shaped fiber with different cross-section. The impacts of particle size, inlet velocity, fiber filling rate, and fiber placement were investigated on particulate matter capture efficiency for shaped fiber with different cross-section. The results showed that the capture efficiency of shaped fibers was increased with particle size, when particle size was 0.5~2.5 μm and inlet wind speed was 0.5 m·s
. The capture efficiency greatly increased for particulate matter larger than 1.5 μm. When inlet velocity was 0.2~0.6 m·s
and particle size was 2.5 μm, the particle capture efficiency of shaped fibers was increased with inlet velocity. When the filling rate was 1.2%~4.0% and particle size was 2.5 μm, the particle capture efficiency of shaped fibers was increased with filling rate. The highest capture efficiency was achieved in the case of shaped fibers with cross-section of equilateral triangle. With the same radial deformity, the capture efficiency is higher when the edge perpendicular of the shaped fiber is parallel to the airflow direction. The impact of fiber placement on the particle capture efficiency was reduced with a smaller radial distortion coefficient of shaped fibers. The outcome of this study could inspire the fabrication of new fiber filter materials.
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Computational domain and boundary conditions
Schematic diagram of fiber cross section shape
Schematic diagram of fiber placement
The relationship between pressure loss and grid number
The relationship between dimensionless drag force and Reynolds number
Verification of particle capture efficiency of circular fiber with filling rate of 4%
2种放置方式下颗粒物粒径对不同异形纤维捕集效率的影响
Impact of particle size on the capture efficiency of shaped fibers under two placement conditions
2种放置方式下入口风速对不同异形纤维捕集2.5 μm颗粒物效率的影响
Impact of inlet wind velocity on the capture efficiency of shaped fibers under two placement conditions
2种放置方式下填充率对不同异形纤维捕集2.5 μm颗粒物效率的影响
Impact of filling rate on the capture efficiency of shaped fibers under two placement conditions
Parameters of different cross-sectional shapes fibers of the alien degree and shape factor
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