Comparison of stereoscopic particle image velocimetry and volumetric particle tracking velocimetry in the wake of a ducted propeller

Abstract

The interaction of ship and waterway is of utmost importance in inland navigation. Regulations and waterway maintenance rely on assumptions for the damage potential of propeller jets. Scours are to be avoided or repaired at an early stage. As preparation for the validation of future CFD simulations, measurements were carried out in the propeller jet using different methods.2D3C PIV is a non-invasive method for flow measurements in a 2D plane. However, for applications with transient flows, volumetric measurements are desired. Previous Particle Tracking Velocimetry systems suffered from low resolution and difficulties with high seeding density. The system used here attempts to overcome these disadvantages with the Shake-the-Box algorithm and a new hardware design. The focus is on comparing this volumetric flow measurement technique with conventional 2D3C PIV. The test case is the wake flow of a ducted propeller in bollard pull condition.Since the tests were carried out in different facilities, the measured flow fields are not fully comparable. Nevertheless, it is shown that the method is suitable for phase-averaged measurements in addition to the advantages in three-dimensional flows. The findings from this first series of measurements are used for the further development of the system.