Hi Everyone,

Due to some model restrictions, I have a 32 bit controller which requires me to use an older version of OpenFAST (v2.4).

I was interested in checking the global/fixed frame hub loads (in newer versions it would be "RtAeroFxg, RtAeroFyg, RtAeroFzg, RtAeroMxg RtAeroMyg, RtAeroMzg”. but these parameters are not outputted in this older version.

However, I do have the rotating hub loads "RtAeroFxh, RtAeroFyh, RtAeroFzh, RtAeroMxh, RtAeroMyh, RtAeroMzh” and would like to do some calculations to convert these loads accordingly.

What are the specific equations for this conversion between co-ordinate systems? I had a look through the Aerodyn docs but couldn’t find any information.

My understanding based on looking at the source code is the multiplication of a rotation matrix (containing information about the pitch and yaw angles) and the load vectors, my hand calculations are usually fairly close in terms of x and y directions but off in the z direction when I expect a purely negative response due to weight.

Thank you,

Dylan