Propeller wake analysis in non uniform inflow by LDV phase sampling techniques

A laser Doppler velocimetry (LDV) phase sampling technique is developed and adopted for the analysis of the flow upstream and behind a four-blade, highly skewed installed propeller in the case of a twin-screw ship model in a large circulating water channel. The technique implemented allows the reconstruction of the 3D flow field as a function of propeller angle in transversal planes located as close as possible to the blade trailing and leading edges. The main features of the propeller installation are highlighted, as well as the strong and complex interaction of the propeller with the hull wake, especially in the brackets region. The high level of detail and accuracy of the data acquired would be a powerful tool for the development and validation of computational codes applied to this topic.