CFD based vortex generator design and full-scale testing for wake non-uniformity reduction

Abstract

Propeller-induced vibration on ships may originate from separation and wake non-uniformity and can be dealt with stem form redesign, wake adapted propeller design or wake modification devices such as fins, ducts or vortex generators. For an existing ship, the retrofit options are limited and vortex generators are the most cost efficient measure with quick and easy application. However, selection of the design parameters such as size, location and angle of attack relative to the flow are still not straightforward and can be very costly to be evaluated by model tests or full scale investigations. RANS based CFD methods can be used effectively to select these parameters. Current research presents a methodology through a full-scale test case consisting of initial numerical flow calculations and full scale testing, CFD calculations, final numerical flow calculations and full scale testing which shows significant improvements on the wake non-uniformity hence the suffered shipboard vibration.