Learning Forum

[liaa0811]

Hello! I have a simple question.

So, I have this kind of simple module, where there is a distribution pipe in the middle of the module with orifices. I already combine (using boolean) the fluid body (between inside the orifice pipe and the bigger module) and only set the wall boundary on the outer part of the module. Inlet and outlet are located on each end of the distribution pipe.

[Rob]

Can you check you've not set the shell side as a solid and that it's connected (ie you have mesh and no walls) to the perforated tube. n

[liaa0811]

Yes, I combined the shell side and inside the perforated tube (union) and set it as fluid. It?s supposed to be connected since I use boolean union for the inside tube and outside ; then boolean subtract (with preserving the tool bodies) between the fluid body to solids (fibers + perforated tube). Any other idea/ boundaries that I have to check? Thank you!n

[Rob]

Put a mesh slice through the domain on a xy plane to see if there is mesh through the holes. Also check you've got walls and wall-wall:shadows where you expect them to be. n

[liaa0811]

@Rob Yes, I checked and there is mesh on the hole's wall (perforated hole wall), however the wall-wall:shadows seem to be weird.... Is there anything wrong with the meshing? Or in the geometry should I not boolean (subtract) the fluid body and solids? Like, let them be there without substracting the bodies. nand just now, I found a video tutorial similar to my case, and I think almost everything is similar (except materials) but mine does not work Thank you! (and also I imported geometries not making them in DM)nThank you!n

[liaa0811]

Sorry for the late reply. Yes, I am working with STL. do you have any idea about this? Or is it better to create the new model in the design modeler?n

[Rob]

It may be a translation issue, as stl doesn't always work well with the more traditional CAD kernels. SpaceClaim is much better with stl as it's got some faceted tools built in. nThere isn't a simple answer for when to use stl/CAD import over rebuilding from scratch. I take the approach that if it's quicker to rebuild I'll do that, otherwise I'll fight/patch the supplied CAD model. In this case, the geometry is fairly simple so I'd always build from scratch. However I regularly use stl for terrain and human body parts modelling.

[liaa0811]

Alright! I will work on it first and build from the scratch~ Actually, in the future, I will go with more complex features so I prefer to use STL that's why I tried to just use STL file. Thank you for the feedback! That means if the translation issue is not a problem, all of the setup and boundaries are correct, right? n

[Rob]

I'll not say they're all correct, more that they may not be the cause of your problems here. nWhat happens if you turn those wall & shadow pairs to interior zones in Fluent? It could just be a odd surface definition. n