Questions regarding Hydroelectricity

[njust1ce4all]

I'm currently doing a physics investigation into the factors affecting the efficiency of a small hydroelectric generator. In particular, I am investigating the effect of pipe diameter on the energy and power output. When I graph pipe diameter against efficiency I get a shape roughly resembling a parabola, with the peak efficiency somewhat in the centre. In trying to explain this, I am wondering what the significance of friction is on the energy losses. For example, will the percentage friction loss change with the rotational speed of the turbine?

 

[Vailanor]

Or will the friction loss remain constant regardless of the pipe diameter?The friction losses in a hydroelectric generator depend on many factors, such as the turbine design, the pipe diameter, the fluid flow rate and the fluid viscosity. Generally, the larger the pipe diameter, the higher the fluid flow rate, resulting in higher frictional losses. However, the frictional losses will also depend on the rotational speed of the turbine, as a higher rotational speed will increase the velocity of the fluid, leading to more energy being lost due to friction. In addition, the fluid viscosity can play a role in the overall efficiency of the turbine, as higher viscosity results in increased frictional losses. Therefore, it is likely that the friction losses will change with pipe diameter, as well as with the rotational speed of the turbine.