Insonsistent Patch and patchFieldType

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1

Ok, I am getting immensely frustrated because I am unable to troubleshoot this problem on my own through some unfortunate combination of missing knowledge, documentation, or access to generated files/data.

Here is the link to my project with a simple successful analysis: https://www.simscale.com/workbench/?pid=7823935545470138655#tab_1-0

The successful simulation is an incomrpessible, laminar steady state analysis of flow through a valve body. I utilized a hex-dominant automatic mesh, and was only successful when I calculated the mesh without grabbing the inlet and outlet faces; assigning those inlet/outlet boundary conditions of an inlet flowrate and fixed pressure and outlet flowrate respectively in the simulation designer. The simulation computed successfully and ran as expected.

The next step in better understanding both our product and this software was to run an incompressble, turbulent steady-state analysis (my plan is working gradually up through the complexity. My goal is to run a convective heat transfer turbulent, transient analysis, but I want to see all of the levels of complexity and the results from those simulations before getting to that point). Repeating this process with a handful of different meshes, a few different boundary conditions, and several attempts all fail to yield a simulation that can even be successfully calculated. I am continuously given this error: SimScale Documentation | Online Simulation Software | SimScale

I cannot locate, in the documentation, forums, or elsewhere, any guidance on how I can troubleshoot this problem. If I had access to the files generated at each step along the way (Actual mesh data, not just the logs generated), i’m not afraid of poring through the data to figure out which faces are being inconsistently meshed, and figuring out what I need to alter in my setup approach to prevent this problem. I have another project where I’ve tried a few other attempts to set up a turbulent problem, and I just do not understand where my mistake is. It could very well be a conceptual failing in not properly settting up boundary conditions for turbulent flow simulation (which admittedly is beyond my body of knowledge; the furthesy I understand is a graduate-level understanding of viscous laminar flow as treated in most fluids 501 classes).

Any and all help and guidance would be appreciated!!! I look forward to responses offering constructive guidance and criticism in my meshing, my simulation set-up, or somewhere else where my project is flawed (Hell I even changed my imported cad from an Inventor *.ipt file to a *.stp file which actually worked…)

Thanks

Stefan

2

Hey @ssoder

i have take a look at you project and copied it, i’ve done some fixes on the boundary conditions and its ruining well.

set your inlet boundary condition K and omega value to “set gradient to Zero” and set a wall boundary condition on fluid to pipe contact area. as i am writing this post the simulation finish computing you can find it [here.] and last note when you prepare your mesh for turbulant simulation add some layer to it.

Regard
Anwar

1 Like
3

Thank you so much for the guidance. I will implement those suggestions and see where that gets me.

That being said, why? from a theoretical standpoint, what does setting the gradient of k/omega to zero do for the model such that it runs with that BC but not without? As I said I am unfamiliar with turbulence modeling in general, and looking to learn what I can.

Additionally, how do I add wall layer to my mesh? I didn’t see an option for that in hex-dominant automatic mesh setting; should I be using a different meshing option for turbulent problems? If hex-dominant parametric is better then I can definitely spend the time going through those tutorials to better understand that meshing option.

Thanks

Stefan

4

regarding your first question you can find why we set to Zero gradient on theis Doc. and yes you cant find it on automatic mesh. you can add layer using hex dominant parametric algorithm under refinements. you should spend time on it; it gives you more control on your mesh.