Turbine Documentation for GRINS theory doc

[nicholasmalaya]

Absolutely no rush here, this is not and cannot be blocking. But I wanted to propagate back some of the turbine modeling. This is a good first point of consideration for operating the averaged_fan or turbine in GRINS, as well.

We will probably want to expand this section to detail the turning vanes and penalty method in general, as without that it might not be clear why this is formulated as a body forcing (or actuator disk, really) versus meshing turning turbine blades.

[roystgnr]

Can you put that graph in as an octave or matplotlib script?

Aside from all the usual "don't commit intermediate output" and "don't not commit sources" reasons, that plot of the interpolant on C_l doesn't look right and I'd like to check it by more than eyeball. The graph appears monotonic up to pi/4, whereas the interpolant equation has a huge discontinuity at pi/24.

[nicholasmalaya]

Good catch: this was wrong. I just pushed a new directory, 'routines' with a file entitled, 'flat_plate.py' that reproduces the plot. I did not use the curves noted in the document but rather just a higher order polynomial. This was mostly because it also generates a sane interpolation curve for the semi-circle plots (see below), not because @roystgnr's drag polars were not useful (they were).

Obviously some error here, but good enough for first passes through the optimization space. Either way I've altered the text in the document to reflect this.