Effect of Propeller Tip Clearance on Hull Pressure Pulses
Paper i proceeding, 2017

The objective of this study was to investigate how hull forces and pressure are influenced by small propeller tip clearance by creating a setup where systematic variation of tip clearance could be achieved at similar propeller conditions ; in this study, clearances between the propeller tip and a generic hull with tunnel configuration were 0.7%D P , 5%D P , and 20%D P. Simulations were performed using a scale resolved PANS approach, combined with cavitation modelling considering the fluid as a mixture and incorporating mass transfer source terms. The predicted impact on hull pressure is very large, with the maximum amplitude differing an order of magnitude between the small clearance case and the one with normal clearance. More important, however, is probably the forces exerted on the hull plate, and here the difference is much less; the standard deviation of pressure variation differs by a factor that does not exceed two. However, the higher order blade passing frequencies are much more prominent in the case with small clearance, presumably due to a complex behaviour of the tip vortex along the hull plate.

hull pressure

PANS

hull forces

Propeller cavitation

Författare

Rickard Bensow

Chalmers, Sjöfart och marin teknik, Marin teknik

Robert Gustafsson

Rolls-Royce (Swe)

5th Int. Symposium on Marine Propulsor

Low Energy and Near to Zero Emissions Ships (LeanShips)

Europeiska kommissionen (Horisont 2020), 2015-05-01 -- 2019-04-30.

Drivkrafter

Hållbar utveckling

Innovation och entreprenörskap

Styrkeområden

Transport

Energi

Fundament

Grundläggande vetenskaper

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

Ämneskategorier

Farkostteknik

Strömningsmekanik och akustik