In this case the radius was increased and the twist distribution from the baseline turbine was maintained. Again as radius is increased, the maximum CP increases until some optimum radius is reached and then begins to drop off. The inflow velocity at which the maximum CP occurs increases as radius increases. In this case, while the highest value of CP is exhibited by a rotor of 5m radius, this occurs at a higher inflow speed than we would desire. Again, increasing tip radius and maintaining rotational velocity will result in increased tip velocities and as such, cavitation will become an issue beyond a certain point, depending on your rotational speed and aerofoil choice.
