Characterization of Unsteady Leakage Flow in an Axial Fan

The present work reports an experimental study of the leakage flow in a low-speed fan ring. Existing 2D Particle Image Velocimetry (PIV) measurements taken meridional plane front rotor gap have been further processed and analyzed by means Proper Orthogonal Decomposition (POD). Three values dimensionless pressure rise across investigated. Namely, attention has focused on intermediate case—the one for which strong radial oscillation observed: POD results shown that, this condition, exhibits periodic oscillations that are not correlated to blade passing. Moreover, such coherent motions found promote turbulence transport at different positions, whereas rotor-related negligible effect sense. procedure can be generally applied turbomachinery flows characterize their unsteady behavior beside classical phase-averaging methods based quantities. approach is novel dynamics axial fans.