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

Abstract

In the present study, the wake fields of two full ship models were measured using a twodimensional (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 (L PP ). 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 L PP 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.

Application of a Local Dynamic Model of Large Eddy Simulation to a Marine Propeller Wake

“…Reference [9] conducted experimental research on a small unmanned aerial vehicle propeller with serrated trailing edges, using a high-resolution digital PIV system to measure the flow field and quantify the detailed flow structure around the propeller. Reference [10] used PIV measurements of the wake flow field of a large oil tanker to validate two-dimensional PIV measurements and reconstruct three-dimensional flow fields by overlaying two-dimensional measurements, and studied the influence of rotating propellers on average velocity and turbulence characteristics. Reference [11] adopts a new type of underwater micro PIV system, which utilizes underwater particle image velocimetry and acoustic Doppler velocimetry to in-situ measure sediment resuspension caused by propeller erosion.…”

Stereo Particle Image Velocimetry Measurements of the Wake Fields Behind A Panamax Bulker Ship Model Under the Ballast Condition

“…For bulk carriers, the ballast condition accounts for almost 50% of the total operation time [4]. Our previous paper [2] described in detail the measurement of the wake fields based on the PIV under the design-loading condition, and most of the literature focuses on the flow characteristics around the hulls under the design conditions [5][6][7][8][9][10][11][12][13]. The flow characteristics around the ship under the ballast condition is different from that under the design condition with the change in the draft, inclination angle, and the float status.…”