Comparison of full-scale PIV measurements with CFD simulations of a ship propeller inflow

Flow around the ship's hull and specifically the inflow conditions of the propeller(s) critically influence the propeller efficiency and cavitation behaviour. In a typical single-propeller vessel, the hull of the ship creates a velocity deficit in the top part of the propeller disk. In this relatively limited region, the velocity vectors have a different angle of attack with the blade leading edge than what the propeller was designed for. This creates suitable conditions for cavitation, which is the main source of noise and vibration both inside the vessel as well as in the marine environment. In order to accurately predict this critical part of the flow, CFD simulations have a requirement for validation data. Recently, full-scale measurements of the flow around a ship were performed by [1], [2], [3] and [4]. Such data was also recently acquired within the JoRes joint industry project (JIP), where the current authors applied a novel full-scale stereo-PIV device (called 'FlowPike') onboard a large sailing vessel. Initial results were presented in Birvalski et al. [5]. The current
study uses the same data, focusing on two new aspects: 1) quantifying the uncertainty of the PIV measurements by using both the measurements performed at MARIN and at sea, 2) presenting first comparisons between the PIV results and CFD simulations of the full-scale flow.