三维PIV技术在吸入涡流态测量中的应用

Application of 3-D-PIV in measuring the entrained vortex

为了研究进水口前吸入涡的流动特性以及不同结构的进水口对吸入涡的影响,对水平进水口前的吸入涡流动进行了三维PIV测量。测量时应用折射率校正法解决了不同介质中进行三维PIV试验时所产生的粒子成像不清晰的问题,并采用多次成像标定法来减小垂直方向上的速度测量误差。通过该试验,得到进水口前吸入涡的三维速度分布规律,并得出后壁面角度与吸入涡大小和强弱关系。试验表明,后壁面角度为30°的进水口比角度为0°进水口更能有效的阻止吸入涡发生,因此可以通过加大后壁面的夹角的方式来削弱进水口处的吸入涡。

In order to study the entrained vortex flow and get the influence of the structure of the intake on it, the 3-D-PIV technique is used to measure this kind of flow near the horizontal intake. The image of the particles got by 3-D-PIV experiment in two media is unclear for the difference of refractivity in different media. So the refractivity-revised method is used to solve the problem. And the multi-step calibrated method is used to improve the measurement precision of the w vector. In the experiments, the distributions of the 3-D velocities of the entrained vortex are obtained. The relation between the entrained vortex and the structure of the intake is also found. Results show that the intake with 30° angle chest wall can prevent the entrained vortex effectively than that with 0° angle chest wall, so it is a good idea, through changing the angle of the chest wall, to prevent the entrained vortex near the intake.