replecating propeller geometry from photos

[jybb]

Hello all,

I'm trying to roughly match this propeller geometry by photos.

Could anyone please suggest the chord and twist parameters and if it's possible to get this swept tip shape?

[Cibin Joseph]

Those look like DALProp Cyclone Propellers. There are most probably no details on their blade geometry online. 

I would try the UIUC propeller database. If you are required to model the exact geometry, your best bet would be to find a 3d model somewhere and figure out the twist and chord distributions.

Let me try a hand at replicating the approximate blade geometry. It would only be an aesthetic match at best.

- Cibin

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[jybb]

Those are Gemfan hurricane 3520, I couldn't find blade geometry for any of the micro quadcopter propellers online.

Thanks for suggesting the UIUC propeller database i'll have a look, with photos I only need a rough approximation.

If I could get it 3D scanned is there a method to find the right airfoils?

[jybb]

I would like to use this propeller https://www.apcprop.com/product/7x5e-b4/

I've downloaded the geometry data from https://www.apcprop.com/technical-information/file-downloads/ but how do you import it into OpenVSP?

[Rob McDonald]

Wow, that is a great data set.  I was unaware that APC made such great data available.

I would recommend you write a script in either OpenVSP's scripting language or Python to read those files and then use the BEM import capability to generate the propeller geometry.

Rob

[jybb]

Yes I was surprised to find it available, would be great if all manufacturers shared their data!

Thanks for your suggestion but is there a way to do it without coding knowledge? maybe a BEM template file and copy the values from the .peo file?

[Rob McDonald]

Sure, you could do that.

Start with a generic propeller -- just add the default and don't change any settings.

Then, export a BEM file for that propeller, that will show you the format OpenVSP expects.  Delete all the airfoil information after the blade definition -- OpenVSP doesn't import that part anyway.

Use that as a guide and re-format the APC data to look like the OpenVSP BEM file.  That file should import without issues.  You can then set the airfoils in the OpenVSP GUI.

Rob

[jybb]

Awesome, thank you Rob!

[James H.]

Hi all,

I ended up making a quick APC (PE0) to BEM converter script for anyone who's interested.

https://github.com/jamesjhu/APC2BEM

Cheers,

James

[Rob McDonald]

Awesome.  Thanks for doing that and for making it available.  I look forward to trying it out.

Rob

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[jybb]

This is great, thanks for sharing it!

[James H.]

Thanks, hope it helps. Definitely LMK if you guys find any bugs. I compared an output 19x12E prop in OpenVSP with a top view from the UIUC props database and visually (geometrically) they seem to align pretty well.

Cheers,

James

[Bonifaz Bryant]

Hi James,

I tried the APC (PE0) to BEM converter script you shared on Github, and I also installed the relevant package according to your instructions, but when I enter the conversion command code it gives an error in the terminal（As shown in the screenshot below）.I don't knowing where is causing the error, I want to know is this where I am doing something wrong?

Best regard,

Eric

James H. <jame...@gmail.com> 于2022年10月5日周三 13:58写道：

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[James H.]

You need to call apc2bem.jl from the command line and not from the Julia REPL

[Bonifaz Bryant]

Hi James,

I still got the same error as before，where should I go from the command line, can you please describe in detail? thank you very much!

Best regard,

Eric

James H. <jame...@gmail.com> 于2022年10月6日周四 12:10写道：

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