螺旋桨空泡体积测量

螺旋桨背片空泡分布形态、变化趋势、面积、厚度、体积变化率对研究桨叶剥蚀、螺旋桨噪声及激振力具有重要的意义.通过双目立体视觉的计算机技术,利用两台不同角度的摄像机采集同一时刻的桨叶背片空泡,计算空间点在两幅图像中的视差,获得该点的三维坐标值,得到螺旋桨空泡面积和体积信息.通过连续采集空泡图像信息并实时处理可进一步得到螺旋桨背片空泡发展趋势和体积变化率信息,为解决降低螺旋桨激振力和噪声、桨叶剥蚀等问题提供了重要的技术检测手段,有助于螺旋桨设计者提供更优秀的螺旋桨方案.

Measurements of Cavity Volume on a Model Propeller Blade

The distribution, variety tendency, extension, thickness and volume variety ratio of propeller blade back cavitation are very important to research the blade erosion, propeller noise and hull excitation. This paper describes a highly advanced method of computer technique based on binocular stereoscopic vision to measure the three-dimensional cavity volume and extension using a laser beam coupled with two CCD cameras. According to the technique, two pictures of blade back cavitation are screened by two cameras from different shooting angles. Then the visual difference between the two pictures for the same space point is calculated, and the three-dimensional coordinates of the space point is obtained. Furthermore, the cavitation extension and volume could be calculated quickly. The variety tendency and volume variety ratio of back cavitation could also be obtained through continuously shooting the cavitation pictures and dealing with them in real time, which provides a significant test method for investigating how to reduce excitation and noise, avoid blade erosion and so on.