Tip Speed Impact on Marine Life
For marine mammals such as a seals, which can fit between rotating turbine blades, it is important to consider rotational speed. Since blades are not cutting through the water but rather moving with the water it will be possible for mammals to flow through the gaps in which the water is flowing or pushed out of the way due to fluid dynamics. Larger mammals that do not fit between blade spacing and are unable to react in time can endure injury from impact. This group did not come across studies regarding tidal current turbines, but have found that boat propellers which create a suction effect have been known to harm marine mammals due to their high speeds. In many cases larger mammals tend to avoid propellers due to noise created by singing or cavitation. Unlike maritime propellers, tidal current turbines are designed to avoid high speeds in order to extend blade life. All rotors designed in this project were assessed for a rotational speed of 25 RPMs which correlates to 2.4 seconds for one rotation. It is a suggestion by this group that research regarding the addition of noise or light emitters onto a turbine be performed.
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