Learning from humpback whales for improving the energy capturing performance of tidal turbine blades

Time 
01/25/2017 - 15:00-01/25/2017 - 16:30
Room 
Sasakawa Auditorium

Authors

Weichao Shi
(Newcastle University)
Mehmet Atlar
(Strathclyde University)
Rosemary Norman
(Newcastle University)

Theme

Speaker(s): 
Weichao Shi

The wavy leading edges or leading-edge tubercles of the humpback whale flippers can provide these large mammals with an exceptional manoeuvrability especially in securing their food. A wind tunnel test of a replica of these flippers has revealed that the leading-edge tubercles have largely a 3-D benefit for the finite hydrofoils, which can maintain the lift, deduce the drag and delay the stall angle. Afterwards, the concept has first been applied on wind and tidal turbine with the aid to improve the efficiency and the cut-in operating speed.

The paper is to demonstrate the effect on tidal turbine performance by applying these wavy leading-edge. Within this framework, an experimental test campaign has been conducted in Emerson Cavitation Tunnel, Newcastle University.

A set of tidal turbines with different leading-edge profiles was manufactured and tested to evaluate the hydrodynamic performance. The results showed that the models with the leading-edge tubercles had higher power coefficients at lower tip speed ratios (TSRs). Therefore, the tubercles can reduce the turbines’ cut-in speed to improve the starting performance. The biomimetic concept did not compromise the maximum power coefficient value of the turbine, being comparable to the device without the tubercles, but shifted the distribution of the coefficient over the range of the tip speed ratios tested. And several findings regards to various aspects of hydrodynamic performance will be elaborated in the paper.