Not show the proper value of propeller conditions plot

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Yash Thummar

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Aug 20, 2022, 2:56:13 PM8/20/22
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Hello all,

I am trying to analyse the Airbus Vahana design. Here I am using the battery propeller energy network, and for vertical take-off, I am focusing on the first Hover climb segment. But I got the following errors in the terminal and some in the propeller condition plot.

Rotor BEVW did not converge to a solution (Stall)
Rotor BEVW did not converge to a solution (Stall)
Rotor BEVW did not converge to a solution (Stall)
Rotor BEVW did not converge to a solution (Stall)
Rotor BEVW did not converge to a solution (Stall)
Segment did not converge. Segment Tag: hover_climb
Error Message:
The iteration is not making good progress, as measured by the
  improvement from the last ten iterations.
Rotor BEVW did not converge to a solution (Stall)

Propeller.png

I think I got these errors because of some problems in propeller design. But still, I cannot find the solution. Can someone help me with this problem?

I attached a Code and a plot of propeller condition that I got.

Thank you in advance,
Yash
Batt_prop_VA_Hover.py

Emilio

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Aug 25, 2022, 9:30:26 PM8/25/22
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Hi,
A couple of things. First the mission iteration is being skipped. Remove this line: segment.process.iterate.unknowns.mission = SUAVE.Methods.skip

Also check the rotor sizing. It's set for 100 kts and 45000 watts. That's very high. Look at this example rotor for a vahana like vehicle.

-Emilio

Yash Thummar

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Aug 26, 2022, 3:10:19 AM8/26/22
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Thank you so much, Emilio, for your reply.
 
I made changes in freestream velocity and Design thrust. But, still, I got the same error. So,  I will now try to change the vehicle setup and include the vehicle config.

Thanks for sharing the Tiltwing vehicle example. 

Yash Thummar

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Aug 26, 2022, 4:30:34 AM8/26/22
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Now it works.

Can you tell me what is the use of freestream_velocity in propeller design? I mean that which velocity do we have to consider? Does it the same as we consider it in External CFD?
and Does it have the same use in lift rotor and Propeller design?
or in both case context of freestream velocity is different?

I didn't find many resources to understand how it uses in propeller design.
it's good if you can provide some resources for the same.

Thank you,
Yash

Emilio

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Aug 29, 2022, 3:07:54 PM8/29/22
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Hi Yash,
When you design the propeller you're designing the chord and twist distribution. Not all propellers are the same. Some are for slow speeds and some are for high speeds. I don't know your application so I don't know what velocity to pick for your design.


-Emilio

Yash Thummar

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Aug 29, 2022, 3:47:49 PM8/29/22
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Okay, Thank you so much for sharing the paper.
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