Application of vortex generators in ship propulsion system design

An experimental study of vortex generators for hydraulic applications has been performed. The mixing obtained by the presence of the vortex generators has not been addressed at this stage, but the main purpose of the study has been to get insight into the effects of cavitation occurring about the device. Three different vortex generator principles has been used, two with sharp leading edges and one smooth model with less added wetted area, in order to gain understanding of the geometries influences on the vortex generator design. The experiments showed that the geometry of the vortex generators was very important, both concerning the mixing that could be visually observed, and concerning the cavitation patterns. It is concluded that application of vortex generators in e.g. waterjet inlets is both possible and advantageous, but that the devices should be used with great care.