Add 3D wind field

[ufechner7]

Add a turbulent wind field based on https://github.com/OpenSourceAWE/AtmosphericModels.jl .

Idea:

1. Define inflow velocity, turbulence intensity, vertical wind profile and wind direction
2. a function to determine the wind vector as function of x,y,z and t exists
3. write a function to determine the rotor effective wind speed as function of x,y,z,t and the rotor radius
4. do the same for the wind direction
5. do the same for the turbulence intensity
6. allow the inflow velocity to be a function of the time

[MarcusBecker-GitHub]

Is my understanding correct that you want to use AtmosphericModels.jl to generate a background flow field for the wind farm?

In that case, I'd implement it as a source for the wind correctors and have them read the data in and modify the WF states accordingly. The OPs have the wind speed & direction states, as well as TI, the shear profile can be handled by the Shear_interpolation function.

The rotor effective wind speed as a function of x,y,z,t, and the rotor radius is then handled automatically by the FLORIS model.

[ufechner7]

I have a new, slightly different idea:

1. create a 3D wind field. At each point, store a tuple of the wind speed vector and the turbulence intensity, but do NOT include the turbulence in the wind speed vector. This vector shall only carry magnitude and direction of the wind speed.
2. as inflow conditions, assume wind speed, direction, turbulence intensity and wind sheer at the inflow plane. The position and orientation of the plane must be specified with one location and an angle a little bit in front of the wind farm.
3. the inflow conditions can be time dependent
4. provide a function that calculates wind speed, direction and turbulence as a function of time at the locations of the turbines at hub height.