RoughProp - reduction of underwater noise from ships by surface roughness
| Reference number | |
| Coordinator | CHALMERS TEKNISKA HÖGSKOLA AKTIEBOLAG - Institutionen för Mekanik och Maritima Vetenskaper |
| Funding from Vinnova | SEK 1 402 000 |
| Project duration | November 2018 - July 2020 |
| Status | Completed |
Important results from the project
The purpose was to investigate the possibility of commercially using surface roughness on a propeller to weaken the propeller´s tip vortex and thereby reduce radiated noise. The project has successfully increased the understanding of how roughness affects the tip vortex and has thereby been able to develop a design philosophy to select suitable areas for the application of roughness. For the propeller used in the study, the cavitation onset has been significantly delayed. The results are promising and can be used as a retro-fit solution for vessels that have specific requirements.
Expected long term effects
A design methodology for using surface roughness to affect the propeller tip vortex has been developed. For the propeller that has been examined, this has led to a significantly later start of cavitation over the entire area of operation. However, the efficiency loss is considered to be slightly too high for it to be of interest to all customers, but the technology is mature to be applied to vessels with specific issues or requirements. Further studies are planned to investigate whether it is possible to avoid the reduced performance and thus be able to offer more customers the technology.
Approach and implementation
Initially, detailed studies were conducted on an isolated wing, both through numerical simulations and through experiments. This case was used both to develop and validate simulation models of different accuracy and to increase the physical understanding of how roughness affects the tip vortex. In step 2, computer simulations were used to evaluate how different types and locations of roughness affect the tip vortex and performance of a commercial propeller. This work has also been the basis for developing a design methodology to use in new cases.