Experimental method of three-dimensional velocity field measurement in circular pipe based on PIV

Particle image velocimetry (PIV) is a new flow measurement technique, which develops based on traditional flow visualization technique and image processing method. Fully developed velocity field in circular pipe is selected as measurement object. For two-dimensional PIV system developed by Beijing Cube World Technology, affection of cross-frame time on measurement results is discussed. Furthermore, determination method of best cross-frame time is proposed, with which measurement error decrease maximum 30%. Besides, three-dimensional velocity field reconstruction method based on two-dimensional PIV system is studied. Through flow field measurement on a plenty of orthogonal planes, linear interpolation and cubic spline interpolation method are selected to increase three-dimensional data points. Experimental results show that measurement accuracy with two interpolation methods are both less than 5%. It is verified that the reconstruction method is practical.