再生水滴灌毛管内颗粒-管壁碰撞特性研究

Particle-Wall Collision Characteristics Influenced by Biofilms in Drip Irrigation Laterals with Reclaimed Water

利用三维白光干涉形貌仪对滴灌系统中光滑毛管管壁、未使用过的毛管管壁、附生生物膜的毛管管壁3种壁面进行表面形貌测试,在此基础上借助相位多普勒粒子分析仪研究了3种壁面条件下,3种粒径颗粒与壁面碰撞规律。结果表明:生物膜管壁的比表面积(212%)显著高于毛管管壁(4.37%)及光滑管壁(0.196%);细颗粒(粒径为10μm)与光滑管壁碰撞的平均速度低于生物膜管壁,且表现出光滑管壁、毛管管壁、生物膜管壁速度概率分布逐渐变宽的趋势,而中(粒径为50μm)、粗(粒径为100μm)两种颗粒物平均速度接近于零,概率密度分布未出现明显变宽趋势,说明附生生物膜对粒径高于50μm的颗粒物运移影响不显著。

The Phase Shift Micro XAM -3D was used to measure the roughness of smooth wall, new lateral wall and lateral wall attached by biofilm. The phase-Doppler particle anemometer was used to measure the particle movement with the effect of different walls. The study used three different particle sizes： 10 μm, 50 μm, 100 p.m under three different walls. The results showed that the surface area of biological lateral wall （212%） was significantly higher than that of new lateral wall （4. 37% ） and smooth wall （0. 196% ）. The velocity of small particles （particle size of 10 μm） collided with smooth wall was lower than that collided with the biofilm lateral wall. The velocity distribution of smooth wall, new lateral wall and biofilm lateral wall tended to be gradually wider and wider. While the average velocities of middle particles （50 p.m） and big particles （ 100 μm） are closed to zero and didn＇ t widen. The reason is that the biofilm enhanced the surface adsorption capacity which reduced the number of small particles. The result proved that the effect of biofilm on big particles was not significant.