RoughProp - reduction of underwater noise from ships by surface roughness
|Coordinator||CHALMERS TEKNISKA HÖGSKOLA AKTIEBOLAG - Institutionen för Mekanik och Maritima Vetenskaper|
|Funding from Vinnova||SEK 1 402 000|
|Project duration||November 2018 - May 2020|
|Venture||Innovationer för ett hållbart samhälle|
Purpose and goal
Ship generated noise is today classified as an environmental issue, like emissions to air and water. The main source of this noise is the cavitating tip vortex of the propeller; reducing this problem normally leads to increased emissions of CO2, SOx, NOx, and particulate matter. We will investigate how to mitigate tip vortex cavitation by applying surface roughness to the propeller blade. The goal is to increase understanding for how this solution works, quantify its potential to improve the environment, and propose a design process through which this innovation may be realised.
Expected results and effects
The project aims to find the most beneficial distribution of surface roughness on the propeller that reduces the tip vortex while avoiding significant impact on efficiency. Further, scale effects should be determined, i.e. how big will the difference be for the real propeller compared with model scale tests. Recommendations on how to achieve the surface roughness will be developed, both for new propellers as well as on already delivered ones. Moreover, the impact on the level of noise sources from ships in the Baltic will be studied through simulations performed by FMI within HELCOM.
Planned approach and implementation
The work is founded on a combined analysis through model scale experiments and advanced computer simulations. Initially, the simulation methods will be developed and validated towards existing experimental data. Then, systematic studies will be performed to determine where to apply roughness in order to achieve the best effect for a range of relevant operating conditions for a commercial vessel. The proposed solution will be validated by experiments to be performed in the project at Rolls-Royce AB. Simulations will then be performed in ship scale.