大偏航角航行状态下护卫拖船周围的流体速度矢量场
The flow around a ship at yaw angles beyond thoseencountered during manoeuvres has not been thesubject of much research reported in the literature.These conditions are particularly important for anescort tug, since it uses large yaw angles to generatehydrodynamic forces that are used to control a ship(normally a tanker) in the event of an emergency.This paper presents CFD predictions for the flowaround an escort tug at a yaw angle of 45 degrees andcompares them to PIV measurements of the flowpatterns. The CFD code predicts the essentialfeatures measured within the flow, such as theseparation of the flow from the upstream bilge, andthe formation of a large vortex generated by the lowaspect ratio fin. The predicted vectors were comparedwith the measured ones using a numerical technique,and the agreements were found, on average, to bewithin 10%. This level of agreement was within theestimated uncertainty of the PIV system used for theexperiments.