基于Matlab的超声空化场测量与可视化分析

为探究超声空化机理、明确超声条件对空化效应的影响,采用铝箔腐蚀法,测量了不同条件下槽式与探头式超声装置中空化场分布,在Matlab平台实现了超声空化场的二维可视化,并通过超声基础试验进行分析验证,.结果表明:槽式超声场分布不均匀,随着超声频率的增加,铝箔腐蚀面积减小,空化效应减弱;空化效应在波腹处最明显,高效区面积最大.探头式超声空化场的高效区主要分布在探头轴线附近,随着铝箔与探头距离的增加,空化效应逐渐减弱,低效区面积增加;空化效应随超声波声能密度的增加而增强,声能密度5W/mL时,腐蚀面积可达80%以上.相同条件下,槽式超声波反应器中超声空化效应较强.超声波声能密度越大,处理后的污泥上清液SCOD越高,破解效果好;随着超声频率的增加,污泥破解程度下降,空化效应减弱.

Measurement and visualization of ultrasonic cavitation field based on Matlab

Aluminum foil erosion was used to measure the distribution of the ultrasonic field in both bath and probe sonoreactors under varied sonication conditions, to explore the ultrasonic cavitation mechanism and to clarify the impact of sonication conditions on cavitation effect. Two-dimension ultrasonic cavitation field was visualized based on Matlab software. Then it was analyzed and verified through ultrasonic experimental. The distribution of ultrasonic cavitation field in bath sonoreactor was uneven. In addition, the erosion areas decreased with the increasing of ultrasonic frequency, accompanying a worse cavitation effect. The strongest cavitation effect occurred at the antinode, which responded to the largest effective areas. As to the probe sonoreactor, the effective areas were mainly distributed in the vicinity of the axis of the probe. The cavitation effect gradually became weakened while the inefficient areas increased when the distance between aluminum foil and probe became further. The increasing of ultrasonic density contributed to a stronger cavitation effect, the erosion areas could reach up to 80% at 5W/mL. It was also indicated that under the same conditions, ultrasonic cavitation effect in bath sonoreactor was stronger compared to the probe one. The increase of ultrasonic density led to the enhancement of the concentration of soluble chemical oxygen demand (SCOD), indicating well sludge disintegration effect. The disintegration of sludge and cavitation effect decreased as the ultrasonic frequency increased.