Fuselage loft segment .txt/.csv file import

[Tim Schuhmann]

Hello,

I would like to import a loft segment with a specific cross section. The datapoints for the cross section are extracted from a CAD model. Is this possible in SUAVE and if so what are the commands to include a certain cross section as a segment for a lofted body (Fuselage).

The format for the import would be either a .txt/.csv or .dat file.

Thanks,

Tim

[Daniel E.]

What's the purpose of importing the geometry?

If you need just a rough approximation of the fuselage cross sections then you can try and use the lofted body segments class type.

Look at the X57_Maxwell_Mod2.py for an example. Not sure how you'd handle a higher fidelity import. 

NOTE:Im not a developer. Just a SUAVE user. 

[Tim Schuhmann]

Hi, 

the purpose is to create a SUAVE twin of the CAD model that is already available and change parameters of the current configuration and run some optimizations within a Toolchain I am developing. Basically I am just looking for a way to use a file of coordinates as an input for the loft section of a fuselage. I have already extracted some cross sections from CAD which I then want to use to have an accurate twin in SUAVE/OpenVSP. 

Or is there a way to upload the CAD into OpenVSP and generate a .vsp file which can then be imported into SUAVE?

Thanks,

Tim

[Emilio]

Hi,

Questions regarding the CAD->OpenVSP are best asked in the OpenVSP forum.

As far as fuselage geometry, one thing I'd like to be clear with the limitations of SUAVE is that it is not CFD (unless of course you connect to a CFD code). So adding segments in SUAVE usually has very limited impacts. SUAVE looks at high level parameter of the fuselage to calculate the drag and the weights. What's important are lengths, max heights/widths, fineness ratios, and most importantly wetted areas. The benefit of segmented fuselages is the ability to connect to OpenVSP and get a more accurate estimation of these parameters to feed back into SUAVE.

These limitations are not present in Wing geometries and the small details of each segment and airfoil are used.

So with that knowledge, perhaps for your toolchain all you need to extract are the top level parameters of the fuselage from CAD.

Let us know if you have any more questions,

Emilio

[Tim Schuhmann]

Hi Emilio,

thanks for your input, I found a workaround by using OpenVSP to model the initial design. For future designs I will follow the strategy you mentioned and only use high level parameters. Now another question arose regarding the option in OpenVSP to create a body of rotation. Is it also possible to directly create a body of rotation in SUAVE?

Also is it possible to change the tip cap type to 'flat' instead of 'round'?

Best regards,

Tim

[Emilio]

Hi,

SUAVE has no equivalent body of rotation. We would need to come up with a way of estimating drag (as well as weights) for any arbitrary body of rotation at any orientation for that to work.

Also the tip treatment in SUAVE is assumed to be flat, the OpenVSP import defaults them to round.

-Emilio