CFTAL tutorial power coefficient overestimated with LeishmanBeddoesSGC model

turbinesFoam / turbinesFoam

Actuator line modeling extension library for OpenFOAM.

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CFTAL tutorial power coefficient overestimated with LeishmanBeddoesSGC model #85

Closed petebachant closed 9 years ago

petebachant commented 9 years ago

This tutorial simulates the UNH-RVAT, which should hit a mean power coefficient of roughly 25%.

The C_P waveform looks the most accurate of all the DS models, but the amplitude and mean values are way off (mean is around 60%). Interestingly, it seems to work perfectly for the RM2.

For reference the min/max power coefficients at TSR = 1.9 should be about 0.10 and 0.45, respectively.

petebachant commented 9 years ago

Ideas for why this is happening:

Neglecting the pitching moment
Errors in flow curvature correction
Using NACA 0021 foil data rather than NACA 0020
End effects
Low mesh resolution causing excessive diffusion of vorticity (maybe try LES)
Poor fitting of the separation point to normal coefficient curve in the LB SGC model at high angles of attack--related to #78
Incorrect empirical constants in SGC model

petebachant commented 9 years ago

Closing until other models are finished.