Possible mistake in force calculation of facetSRPDynamicEffector

[BriekArcsec]

I think there may be an error in the computation of facet SRP forces:

basilisk/src/simulation/dynamics/facetSRPDynamicEffector/facetSRPDynamicEffector.cpp

Line 156 in 4c26e17

facetSRPForcePntB_B = -SRPPressure * projectedArea * cos(theta)

In this equation, both the projectedArea, and a factor cos(theta) are used, which seems erroneous, and in conflict with the equation found on the module page. I think the equation should either use projectedArea, or this->scGeometry.facetAreas[i] * cos(theta)

In the current shape, this equation appears to project the SRP pressure twice (once by using the projectedArea, and once with the factor cos(theta))

[schaubh]

Interesting point, let me look into this further.

[leahkiner]

Yes this is an issue, thank you for pointing this out!

[schaubh]

This fix has been pushed to develop.