Importing From Onshape

[ccosta23]

I have a car I have designed in Onshape
Onshape Car.

However, it is made up of many surfaces and so I cannot simulate the aero does anyone know of a way that I can simulate its aero?
Any help would be much appreciated thanks!!!

[DaleKramer]

This may be more than you need but it does reinforce that you need to spend a lot of time optimizing your CAD files fir meshing…

FSAE Tutorial - Preparing Simulations For Success - CAD Preparation

CAD Preparation Intro Starting at the foundation of a problem free simulation is having the correct CAD geometry. This fact cannot be overstated enough as this has been proven time and time again over the course of testing. Therefore, there are two main concepts that must be understood. Having a correct CAD Geometry has a HUGE IMPACT on the resulting mesh quality. If not prepared correctly, the mesh could possibly fail. A good mesh will result in an accurate simulation. In addition, a bad me…

And here is SimScales basic CAD file documentation:

CAD Preparation & Upload | Simulation Setup | SimScale

[ccosta23]

I know how my file needs to be optimized but I am just not sure how to do it. If you look at the link a lot of my model is just surfaces and I was wondering how to fill them so that it is a solid.

[DaleKramer]

I suggest that you seek help in the Onshape forum to understand how that may be accomplished.

Unless there are Onshape experts here that are willing to help.

I would help if I used Onshape.

[ccosta23]

I have been attempting to use the onshape forum but they don’t seem to know

[DaleKramer]

Well they should know, what you describe is definitely a CAD issue, not a CFD issue.

If you just have surfaces, if you are lucky, the minimum you need to do is join/fillet them until there are no holes left. At that point it will be a solid.

EDIT: I just checked out the CAD geometry that is currently in your project. You have a long ways to go to add surfaces and then join them into a solid. It would take me a LONG time to do so and I have extensive background in solids modeling. Where did all your surfaces come from?

[ccosta23]

I first made a load of sketches and then joined them by using tools to fill the area in between. Also many of the holes are on purpose. At least the large ones

[DaleKramer]

Every surface must be joined along ALL of its edges, including holes, to other surfaces in order to create a solid. Try making a simple cube out of 6 surfaces to see what I mean.

[RicardoParis]

Hello! Just a quick comment: on Onshape you can find the open boundaries by clicking on 'Highlight boundary edges":

The open boundaries that cause the model to be a sheet part are shown in red. These parts are likely going to take quite a bit of work to make solid.

Quick note: in case you are just interested in simulating cars in general (and not exactly this car), you can find a bunch of models in the public projects section. You will also find some car models in the tutorials page.

[ccosta23]

Thanks I am on my way to making it a solid. But ya I am interested in simulating my own designs