基于Tomo-PIV技术的螺旋桨三维强旋转流动的实验研究

Experimental Study on Three-Dimensional Strongly Rotating Flow of Propeller based on Tomo-PIV Technique

流体机械以及水力发电过程中的流动通常是具有强旋流的三维空间流动,此类流动的实验测量具有较大的难度。本文以水下伺服电机搭载三叶螺旋桨产生强的三维强旋转流动为例,采用四台CMOS摄像机同步对流场进行拍摄,并利用搭载了目前国际上最先进的层析粒子图像测速技术(Tomo-PIV)算法的德国LaVision公司的软件Davis 10.2.0对拍摄得到的图像进行空间重构,得到瞬时的三维空间速度场。基于得到的速度场,对螺旋桨三维强旋流结构的瞬时特性和时均特性进行了深入分析,并从速度、涡量和压力的变化上阐述了流场结构变化特点,证明了Tomo-PIV技术具有很高的测量精度和实际应用意义,在流体机械流场测量和水力发电领域三维空间流场的精细测量有广阔的应用前景。

Experimental measurements of three-dimensional swirling flows with strong rotation are challenging,especially in fluid machinery and hydropower processes.In this study,a three-bladed propeller mounted on an underwater servo motor was used to generate strong three-dimensional swirling flow.The flow field was captured with four synchronized CMOS cameras and reconstructed in three-dimensional space using the state-of-the-art tomographic particle image velocimetry(Tomo-PIV)algorithm from LaVision GmbH.The instantaneous three-dimensional velocity field was obtained using the software package Davis 10.2.0.Based on the reconstructed velocity field,the study performed an in-depth analysis of the instantaneous and time-averaged characteristics of the three-dimensional swirling flow generated by the propeller.The changes in velocity,vorticity and pressure were analyzed to demonstrate the characteristics of the flow field structure.The results of the study confirm the high measurement accuracy and practical significance of the Tomo-PIV technique,which has broad application prospects for measuring three-dimensional flow fields in fluid machinery and hydropower processes.