Tilting Propellers and not wing

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Divyam Verma

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Oct 23, 2021, 1:09:34 AM10/23/21
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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

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Oct 23, 2021, 2:34:04 AM10/23/21
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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

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Oct 23, 2021, 2:52:01 AM10/23/21
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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

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Oct 25, 2021, 1:18:21 PM10/25/21
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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

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Oct 26, 2021, 2:32:27 AM10/26/21
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I am using SUAVE 2.4.0. Probably should use the latest version. 

Divyam Verma

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Oct 26, 2021, 2:41:07 AM10/26/21
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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

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Oct 28, 2021, 2:49:15 PM10/28/21
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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

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Oct 29, 2021, 2:12:50 AM10/29/21
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Thanks! But if I want to constrain the AoA, through the whole mission (for e.g. cruise), can I do that?

ebot...@gmail.com

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Oct 29, 2021, 2:35:21 AM10/29/21
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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

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Oct 29, 2021, 5:28:50 AM10/29/21
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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

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Nov 2, 2021, 1:19:31 PM11/2/21
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Yes, you would need a script in Analyses/Missions and Methods/Missions. Most things could be recycled from existing scripts though.

-Emilio

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