Behavior of hydrophobic micron particles impacting on droplet surface
Behavior of hydrophobic micron particles impacting on droplet surface
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DOI：
10.1016/j.atmosenv.2015.05.053
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发表时间：
2015-08
影响因子：
5
通讯作者：
Aolin Wang;Q. Song;Q. Yao
中科院分区：
文献类型：
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作者：
Aolin Wang;Q. Song;Q. Yao
悬浮颗粒物的撞击行为直接影响其在大气中被液滴捕获和工业污染控制过程。通过动力学模型模拟了这一过程，并对疏水微米颗粒进行了分析。在分析能量转换的基础上，提出了以下沉/回弹临界速度（US/R）和回弹/振荡临界速度（UR/O）确定3种撞击模式的判据，并通过动态模拟进行了验证。结果表明，表面张力系数、接触角和颗粒直径是影响临界速度的关键参数，在它们之间存在着回弹速度范围。随着表面张力系数和推进角的增大，U S/R和U R/O增大，回弹速度范围变宽。随着后退角的增大，U S/R保持不变，U R/O减小，回弹速度范围变宽。随着粒径的增大，U S/R和U R/O减小，回弹速度范围变窄。在模拟中考虑的上述关键参数的值涵盖了湿法沉积或湿法洗涤工艺的通常参数范围。模拟结果表明，在这种过程中，颗粒反弹的可能性不可忽视。结合入射速度分布，可以确定气溶胶粒子的附着效率。
The impact behavior of airborne particles directly affects their capture by droplets in the atmosphere and industrial pollution control processes. This process was simulated by a dynamic model and analyzed for hydrophobic micron particles. Based on the analysis of energy conversion, the criteria were developed and verified by dynamic simulation to ascertain three impaction modes by the submergence/rebound critical velocity (U S/R) and the rebound/oscillation critical velocity (U R/O). The criteria indicated that surface tension coefficient, contact angle, and particle diameter are the key parameters to affect the critical velocities, between which exists the rebound velocity range. As the surface tension coefficient and the advancing angle increased, U S/R and U R/O increased, the rebound velocity range widened. As the receding angle increased, U S/R remained unchanged, while U R/O decreased, the rebound velocity range widened. As the particle size increased, U S/R and U R/O decreased, the rebound velocity range narrowed. The values of the above-mentioned key parameters considered in the simulation covered the usual parameter ranges of the wet deposition or wet scrubbing process. The simulation results showed the non-negligible possibility of particle rebound in such processes. The attachment efficiency of airborne particles can be determined by the proposed criteria combined with the incidence velocity distribution.