Innovative design strategies of marine propellers are based on bio-inspired solutions.
In this project high-fidelity simulations will be conducted on the flow across a propeller characterized by tubercles at the leading edge of its blades.
They are small bumps, inspired by the geometry of the fins of the humpback whales, giving them exceptional ability of performing acrobatic maneuvers for catching preys.
Leading edge tubercles are supposed to improve the ability of the boundary layer to withstand separation, improving the performance of propellers, especially in heavy-loaded conditions.
Therefore this technology has great potential of improving the efficiency of propulsion, producing benefits in terms of economy and emissions of pollutants and greenhouse gasses into the atmosphere. In addition, recent studies suggest that leading edge tubercles are able to modify the distribution of pressure over the surface of the blades, limiting the extent of cavitation phenomena.
This feature carries substantial advantages in terms of structural integrity of propellers and their acoustic signature. However, very little information is currently available on this technology, due to the challenge of performing both detailed experiments and computations.
In the framework of the present project, high-fidelity Large-Eddy Simulations on computational grids consisting of about 12 billion points are planned, with the purpose of revealing details on the flow physics across the propeller blades and in their wake, since the modified development of the boundary layer is also supposed to change the wake properties and the mechanisms of its instability.
Simulations will be conducted both on a conventional propeller and a similar, bio-inspired geometry with tubercles, enabling direct comparisons between them.
They are aimed at revealing the effect of tubercles on performance, pressure distribution, unsteady loads, noise and their correlation with the flow physics both across the blades and downstream of the propeller.