Tilting Propellers and not wing

[Divyam Verma]

Hi guys,

I am currently running an aircraft's mission with tilt-rotor as the mission inputs in vertical-take off & climb condition: So basically, in the configs setup I am giving the propeller thrust angle as 90 degrees and 45 degrees for the vertical take-off and climb conditions. 

But upon running, I am getting an ValueError in this line: ut =  ( Vz*np.cos(psi_2d)  ) * rotation. Vz and cos(psi_2d) are of shape (15,24,20) but rotation is (3,).

So should I change the prop.rotation  input with a (24,) shape np.array? Or maybe I am missing something here?

Thanks,

Divyam

[ebot...@gmail.com]

Hi,

The rotation values for a propeller have to do with the direction, like clockwise or counterclockwise. It should be either 1 or -1. Looks like it's getting an array with three values.

-Emilio

[Divyam Verma]

Hi,

Thanks for your answer. So is it possible to use propellers as an energy converter component for vertical take-off & climb configuration or maybe I should define the propeller as a rotor? Because the spin function definition in rotor.py and propeller.py analyzes the geometry differently. Please note that I am trying to simulate a vertical TO, climb and cruise mission of a 2-copter tilt-motor fixed wing design.

Thanks,

Divyam 

[ebot...@gmail.com]

Which version of SUAVE are you working on? We just merged the two, there's very little difference between a propeller and rotor in SUAVE.

-Emilio

[Divyam Verma]

I am using SUAVE 2.4.0. Probably should use the latest version. 

[Divyam Verma]

Hi again,

Also, I had a doubt about angle of attack (AoA) generation while using Fidelity_Zero aero module. I understand that vlm is evaluating a surrogate model for lift and drag coefficient and the function uses AoA as an input. But where is the AoA being generated or updated? Where is theconditions.aerodynamics.angle_of_attack  being initialized?

Thanks,

Divyam

[ebot...@gmail.com]

Hi,

The AoA for the mission depends on the segment type. Usually it's calculate from the flight path angle and the body angle. A typical climb segment will have a specified flight path angle and the mission solver will change the body angle to find equilibrium, thus changing AoA.

-Emilio

[Divyam Verma]

Thanks! But if I want to constrain the AoA, through the whole mission (for e.g. cruise), can I do that?

[ebot...@gmail.com]

You would need to make a new segment type. We haven't had a need for one so far. It's totally do-able to code up and get results however. 

[Divyam Verma]

You mean new mission segment like maybe a 'constant speed constant angle' right? If correct, then I'd have to do scripting in Analyses-Missions, Methods-Missions and Sequential Segments (assuming if I use that) I'm assuming?

Thanks a ton,

Divyam

[ebot...@gmail.com]

Yes, you would need a script in Analyses/Missions and Methods/Missions. Most things could be recycled from existing scripts though.

-Emilio