Creating Mesh Error with Onshape

Good Morning,
i have got a problem with creating the Mesh. This ist the projekt
The Error message says i should look into the Mesh Log, but it has 1500 rows, and i dont now what i looking for.
Plase can you say what is the problem with this model ? I created it in onshape.

Have a nice Weekend

Hi Kai,

So even I struggled to work out where the fluid domain is, never mind a computer :slight_smile:

You can either manually mesh this, explicitly placing the material point in the required area or create a CAD model of the fluid flow (using boolean). This is because at the most complex part, it goes enclosure, space, pipe walls, Internal flow. It would probably work if you used the fine option but who knows which region you would get!

Hope this leads to a sucessful mesh,

Hello Darren,
thank you for your answer. Sorry i wasnt at home on the weekend.

Here is the further explanation :slight_smile:, the model represent a sewer overflow.

Its only a try to simulate it. At the greenarrow the water comes in, at the redarrow the overflow gets out furthermore there is a diameter reduction from 2000mm on 1000mm, at the bluearrow the remaining water flows out too.
So in conclusion:
Solid_1 inlet
Solid_2 outlet
Solid_3 outlet

For the first try i use the Hex-dominant automatic with the Finess “2-Coarse” and 4 Cores. It breaks up and i get no results.

Now i try it on “5-Very Fine” but its still computing…

Maybe i have to change the model ? I created it with onshape and imported it directly from there.


Hi Kai,

Its a really cool model, I think the issue here is that because it is full geometry the computer cant automatically detect where the flow should be. This can be remedied in two ways, create a parametric mesh, and explicitly define the material point within the flow region, or go back to onshape and create a solid that represents just the fluid you wish to simulate and mesh it as automatic internal.

If you get stuck with either of these methods I am more than happy to help,

And if you are sucessful it would be cool if you could write your resolution maybe with the resulting mesh for future reference :slight_smile:


Oh it works, thank you Darren !

The material point was the solution :wink:

Bye Kai

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Great! Good luck with the rest of the project :slight_smile: