# How to link AeroDyn with structural code?

Hi,

I have developed my own simple structural model for blade with MATLAB. Now i want to link my codes with aerodyn to study on its aeroelasticity. Is there any one to know how is it possible to link aerodyn with a structural model? is there anyone have linked aerodyn with his own codes?

regards,

Dear Mehdi,

I’m sure it is possible with a bit of work. Interfacing to AeroDyn v15 would be the most straight-forward. I suggest that you start by reviewing the existing interface to AeroDyn v15, including interface routines AD_Init, AD_End, AD_UpdateStates, and AD_CalcOutput. You’ll have to understand how the mesh data structures in the FAST modularization framework function to pass the input and output arguments to AD_UpdateStates and AD_CalcOutput.

The connection to MATLAB is an added complication; you’ll have to develop an S-Function to call AeroDyn’s fortran code. I suggest you also review how the existing interface between FAST v8 and MATLAB/Simulink functions.

Best regards,

Thanks Jason,

What about getting aerodynamic forces distribution acting on blades through FAST?
How to get them?

Dear Mehdi,

In AeroDyn v15, you can output the applied aerodynamic loads through the standard user interface at up to 9 analysis nodes along each blade. See Appendix E in the draft AeroDyn v15 User’s Guide and Theory Manual for more information: wind.nrel.gov/nwtc/docs/AeroDyn_Manual.pdf.

Within the AeroDyn v15 source code, the applied aerodynamic loads are contained in the y%BladeLoad output mesh.

Best regards,

Sir,
Good day!

Sir, I also have issues concerning coupling.
From the matrix form of M[d^2x/dt^2] + C[dx/dt] + K[x] = F where F covers aerodynamic, centrifugal and gravitational forces, what would be the form of “F” looks like?

For instance, in some general vibration texts, F is sometimes expressed as F= F cos wt.
I’m wondering how F is approached in wind turbine aeroelasticity?

Kind regards,
Wesley

Dear Wesley,

It sounds like what you are asking for is the form of the equations of motion of a wind turbine, including aeroelasticity. The FAST theory basis is discussed in the following forum topic: http://forums.nrel.gov/t/coupled-blade-modes-in-fast/314/1.

Through a FAST linearization analysis, you can get the linearized form your showing (normalized by the mass matrix), as discussed recently in the following forum topic: http://forums.nrel.gov/t/problem-running-test18-fst-in-simulink-by-changing-tmax-using-fast-8-16/1530/50.

Best regards,