卡鲁塞尔氧化沟反应器两相流PIV图像处理研究及实验分析

在单相数字粒子图像测速度(PIV)技术的基础上,研究了PIV两相流动的测试及图像处理方法.利用数学形态学的原理以及互相关法,对两相粒子图像进行标定、识别、区分和流场分析,编辑了相应的软件.并采用此技术对卡鲁塞尔氧化沟模型直道及弯道段二维液固两相流速进行测量,克服了传统点测量方法无法获取全场流动同步信息的缺陷,较好地反映了不同位置处固液流动分布的基本特性.结果表明,沟内径向流速远小于轴向,流速大小相差约一个数量级;同一断面上轴向流动分布是决定水力特性的主要因素;径向流速和水体动能是决定污泥沉积位置的主要因数,固相总体流速小于液相.

Research on the particle image velocimetry for two-phase flow and experiment analysis in Carrousel oxidation ditch reactor

On the basis of the single phase PIV investigation, liquid-solid two-phase flow field particle image velocimetry technique was studied. The two-phase particle image was demarcated, identified, distinguished and the flow flied was analyzed by using mathematical morphology theories and cross-correlation method. The software was designed, then it was applied to investigate in 2-dimensional liquid-solid two-phase flow velocity of straight channel and flexual channel of Carrousel oxidation ditch reactor. The limitations of traditional measurement only to get velocities at single-point and not to acquire the synchronic information of whole-flow-field were overcomed, the preliminary results have fairly well reflected basic characteristics of the liquid-solid movement in different positions. The result show that the radial velocity is less than the axial about decuple, the axial flows are the determinative factors of hydraulic characteristic at the same face. The positions of sludge sediment are primarily depended on radial velocity and kinetic energy. The flow rate of solid is generally smaller than that of liquid.