Propeller tip vortex mitigation by roughness application
Journal article, 2021

In this study, the application of surface roughness on model and full scale marine propellers in order to mitigate tip vortex cavitation is evaluated. To model the turbulence, SST k−ω model along with a curvature correction is employed to simulate the flow on an appropriate grid resolution for tip vortex propagation, at least 32 cells per vortex diameter according to our previous guidelines. The effect of roughness is modelled by modified wall functions. The analysis focuses on two types of vortices appearing on marine propellers: tip vortices developing in lower advance ratio numbers and leading edge tip vortices developing in higher advance ratio numbers. It is shown that as the origin and formation of these two types of vortices differ, different roughness patterns are needed to mitigate them with respect to performance degradation of propeller performance. Our findings clarify that the combination of having roughness on the blade tip and a limited area on the leading edge is the optimum roughness pattern where a reasonable balance between tip vortex cavitation mitigation and performance degradation can be achieved. This pattern in model scale condition leads to an average TVC mitigation of 37% with an average performance degradation of 1.8% while in full scale condition an average TVC mitigation of 22% and performance degradation of 1.4% are obtained.

CFD

Roughness

Tip vortex

Propeller

Mitigation

Author

Abolfazl Asnaghi

Chalmers, Mechanics and Maritime Sciences, Marine Technology

Urban Svennberg

Kongsberg Maritime

Robert Gustafsson

Kongsberg Maritime

Rickard Bensow

Chalmers, Mechanics and Maritime Sciences, Marine Technology

Applied Ocean Research

0141-1187 (ISSN)

Vol. 106 102449

RoughProp - reduced radiated noise to the oceans through surface roughness

VINNOVA, 2018-11-19 -- 2020-05-31.

Subject Categories

Aerospace Engineering

Energy Engineering

Fluid Mechanics and Acoustics

DOI

10.1016/j.apor.2020.102449

More information

Latest update

2/1/2021 1