VSP

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Vigilant1

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Nope. I enrolled to use it a couple of years ago, and dabbled a bit. The amount of work needed to get something useful (not just a sketch but some understanding of the aerodynamics/forces that would be at work on the airplane under various flight regimes, the expected performance, control and stability issues, etc) definitely did not seem like a good exchange. Vortex lattice method--and trying to get the loosely "compatible" other programs to work together to do the work, looked like a lot of challenge and frustration, for a result that might or might not have been applicable.
But I'm sure some people love it.
 

Topaz

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Nope. I enrolled to use it a couple of years ago, and dabbled a bit. The amount of work needed to get something useful (not just a sketch but some understanding of the aerodynamics/forces that would be at work on the airplane under various flight regimes, the expected performance, control and stability issues, etc) definitely did not seem like a good exchange. Vortex lattice method--and trying to get the loosely "compatible" other programs to work together to do the work, looked like a lot of challenge and frustration, for a result that might or might not have been applicable.
But I'm sure some people love it.
+1 as well. With the caveat that my experience was with an early version, I found it very frustrating and counter-intuitive to use. The examples presented seemed to show some powerful capabilities, but the learning curve was more of a "learning Mt. Everest", and the program appeared to be so forcibly "generalized" that doing any kind of rational airplane design process of the kind with which I'm familiar was an uphill battle. I'm sure it's come a LONG way since then - I still get e-mail updates on latest features, etc. - but I didn't find it useful so I haven't gone back.

IMHO, the most useful general tool for airplane design is a spreadsheet. MS Excel, Google Sheets, whatever.
 

drstress

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Aug 12, 2018
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OpenVSP is a fantastic program. It challenges you to be a good engineer... to further your understanding of the "how and why" of your aircraft design. It allows easy and quick reconfiguration of airfoils, cabin sizing, engine/prop placement, empennage sizing and a whole lot more.

This is my latest design using OpenVSP:

Airplane 07.jpg

Spreadsheets are very important in aircraft design. My work in OpenVSP is heavily augmented with calculations using both Raymer and Roncz spreadsheets and hand calculation methodology from Roskam, Torenbeek, Raymer, Bruhn, Niu and Noels.

Before my retirement my last gig was with Boeing working on the empennage for the 787. Virtually all of the analysis was done using spreadsheets.

There is also an important spreadsheet NASA has published to use with OpenVSP: NASA Drag Buildup Workbook. You should get this to go along with OpenVSP.

Finally, the tutorials that go with OpenVSP are not the best. As is typical, software developers don't write good manuals to use their software. They assume that everybody knows what they know. (I think this challenges me to come to their level.)
 

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Vigilant1

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OpenVSP is a fantastic program. It challenges you to be a good engineer... to further your knowledge of the "how and why" of aircraft design. It allows easy and quick reconfiguration of airfoils, cabin sizing, engine/prop placement, empennage sizing and a whole lot more.

This is my latest design using OpenVSP:

View attachment 73526

The work in OpenVSP was heavily augmented with calculations using both Raymer and Roncz spreadsheets and methodology from Bruhn, Niu and Noels.
Wow! May I ask what you have brewing there? We had a very interesting thread a while back regarding the potential for a small centerline thrust homebuilt, and it is still a concept in which I am very interested. We had a few candidate designs, and some numbers crunched via spreadsheet. More here: The Beetlemaster .
 

drstress

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Vigilant1,

Thanks for the interest. I intend to start my own thread about my design. I don't want to go "off-topic" in this thread. I also appreciate the heads-up about "The Beetlemaster" thread. I will read it all.
 

daveklingler

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Jan 22, 2013
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I'm trying to use Mark Moore's AR5 model in the OpenVSP Hangar to generate an STL or IGES so I can import it into SolidWorks. Unfortunately, even though the model says it's V3, OpenVSP 3.21.1 (the latest version) won't load it. Anybody know why not?

EDIT: I get an error message: "document version not supported". I get that for a lot of the models in the hangar. The AR-5 model is version 3, and a model that I got to load successfully is version 4. Anyone know how to load version 3 models?
 
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fly2kads

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I think you might be mixing up the VSP version number and the numerical rating for model accuracy. The AR-5 model that I see in the OpenVSP Hangar has a "Source Quality" of 3, but is for VSP Version 2.X.

To open a version 2.x file in 3.x, use the File... Import menu. Select the button that says "OpenVSP v2 (.vsp)", and then you should be able to open it. It opened for me just now, but the converted model isn't useable "as-is." It would need some cleanup-up prior to use.

Edit: I just remembered the (accurate) comment above about the OpenVSP documentation being somewhat lacking. One positive recent development was the release in April of a new set of tutorial videos that they are calling the "OpenVSP Ground School." They're pretty good, and are a significant improvement over what they had before.
 

daveklingler

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Thanks for your reply.

In the VSP files, which are XML, there's a VERSION tag. The version in the AR-5 model is 3, and the versions of other files I got to load are 4. The VERSION tag doesn't seem to be related to the file suffix and has no bearing on source quality.

That said, you're basically right. :)

I think that a while back when I originally downloaded the AR-5 model, I erroneously changed the suffix to "vsp3". Just recently, I never noticed that the AR-5 was a version 2.x file. I wonder whether I could go back to an older version of VSP and get it to load correctly.

Sigh. I didn't really want to clean up the model, because that entails the open-ended task of learning VSP well enough to do the work; I don't have any idea what that will entail. Well, I'll watch the tutorials and see where it goes.
 
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