Hello, I have been trying to solve an issue with a propeller and think I may have just come up with the solution.

Original problem: Propeller not generating any thrust just drag at 50 mph 900 radians/second yet generating thrust at 0 mph at 900 radians/second?

Probable solution theory: the simulation is not accounting for the wind speed that will spin the propeller at higher speeds. Think of it as a pinwheel, when you run faster the pin wheel speeds up and creates minimal drag. The same thing should be happening with a propeller. As the plane gets faster, the propeller should be rotating faster because of the airspeed. I don’t know if this is the reason why but I would like conformation that this is what is happening?

Thank you for your time, help, and expertise,

Frank lucci

Project links -

https://www.simscale.com/workbench/?pid=7303320169524596296&mi=spec%3A3b367e89-c96b-4f56-9b0f-9d59c42a8fcc%2Cservice%3ASIMULATION%2Cstrategy%3A2 2

https://www.simscale.com/workbench/?pid=4645129274202983280&mi=spec%3Aebe1285f-142d-41ea-a8d0-6ca89fc646c3%2Cservice%3ASIMULATION%2Cstrategy%3A23 1

To also add to this I did a little more reaserch and I found out the the propeller should be producing more thrust because of the airflow?

Hey Frank!

Indeed, the external flow speed should coincide with the propeller operating rpm, otherwise, the power is applied from the flow to the propeller, and not the other way around.

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Thank you, but do you have any idea of how to find the rpm the propeller would be if static at a certain speed to combat this?

Hey Frank!

Sorry for the late reply.

Did you find a way to compute the flow speed from the propeller rpm? I would say that the pitch of the blades should give you the conversion factor. Then, depending on the efficiency of the design, the flow speed should be a little bit lower. You might need to do some trial and error to find the correct value that balances the power provided by the propeller on to the flow.