Turbulent wake field reconstruction of VLCC models using two-dimensional towed underwater PIV measurements

In the present study, the wake fields of two full ship models were measured using a two-dimensional (2D) towed underwater particle image velocimetry (PIV) system to identify the flow characteristics around a hull with a high block coefficient. The 2D PIV measurements and reconstructing the three-dimensional (3D) flow field by stacking the 2D measurements were validated and applied to the model ship wakes in a towing tank. The bare hull wake was measured for a very large crude oil carrier (VLCC) model, KVLCC2, at a Froude number of 0.142 based on the length between perpendiculars (LPP). These measurements were compared with those of five-hole Pitot tubes, a Pitot-static tube, and hot-wire anemometers for validation. After the validation tests, the nominal wake field of a generic VLCC model with a Froude number of 0.145 based on LPP was measured. To identify the effects of a rudder and rotating propeller on the mean velocity and turbulence characteristics, a 3D reconstruction was carried out for the generic VLCC model under self-propulsion conditions.