Optimisation of wind turbine blades in Nepal (Wood and fiberglass)

[mònica sallarès fité]

Hello everyone, my name is Monica. I’m currently working in blade optimisation for an NGO in Nepal. 

The NGO has already bought the wind turbine (Whisper 200) and my task is to try to design improved blades for the project. So, it means that I have the batteries (48 V) controller and generator chosen already.

The voltage chosen is 48 V. The specifications I have from the wind charge controller (Pulse Width Modulation) are attached (see fig.1).

Other specifications are:

The rotor has a diameter of 2.72 m and from field data I know that the average is 7 m/s.

Turbine specifications:

Average power: 570 W at 11 m/s

Rated/voltage: 48 DC High Voltage model

Rated wind speed: 11.6 m/s to 13 m/s

Start-up wind speed: 3.1 m/s

Cut out wind speed: 16-18 m/s

Rotational wind speed: 1200 rpm at rate wind speed

Over speed control: Side furling & dump load

 

See fig.2

 

So, I’ve started the design of the blades with QBlade and I’ve used the average velocity of the field to optimise it. Conserving the same rotor diameter and changing the airfoils used, and verifying that at that velocity, the blades are able to produce the power required.

The think is, that everything is dimensioned to work together so I don’t know if trying to improve the blades at 7 m/s will have good impact in the total performance of the turbine (also because surfaces as the tail had been dimensioned for the specific blades with a specific wind behaviour).

This was my first attempt, now I am thinking to optimise them at 5 m/s and try to be able to produce around 500 W.

 

1.         What do you think? Should I try to go in another direction?

 

2.         I have also tried to reproduce the geometry of Hugh-Piggott in QBlade (just to make a comparison of performances), but I am not able to exactly reproduce the root to the hub because is rectangular (making the edges  curved) but I am still not able to get any polar to later be able to simulate the whole blade. I will attached the project here.

 

Thank you for everything.

 

Regards,

Mònica