So two things to note since the last iteration:
- the base aerofoil was very near stall and was, therefore, causing severe velocity reduction through the blade.
- The interpolation errors are seemingly reduced in the wake field.
The improvements from the first point can be seen by comparing the severity of velocity reduction in the centre of the blade wake. I’m glad that improvements are being shown.
The next thing I wanted to do was to look at the pressure distribution on the surfaces of the blade (front and back) to see where low and high pressures were being formed:
from this we can see that the low pressures are what we would expect generally on the reverse side of the blade however on the front it looks like the blade towards the centre has an unusual pressure distribution. I need to investigate this further.
Next, I also wanted to view the velocity field across the disk and also slightly in front. This was to observe how the velocity slows before coming into the blades disk.
Blade 1 appears to have a different velocity distribution than blades 2 and 3. Not only this, I expected the velocity to be somewhat uniform across the blade. These points also need looking into.
I think I will include the ability to ‘De-rate’ the incoming velocity to get a more realistic twist distribution. I will also include the ability to reduce the cord length, this will be handy for the first and final aerofoils on the blade to get a more ‘manufacturable’ design.
This is how I imagine de-rating to work: