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Why COMSOL use FEM instead of FVM?

Posted July 8, 2021 at 12:49 by Trailokya

Quote:
Originally Posted by mprinkey View Post
FEM lacks a fundamental statement of conservation. FVM (and DG) are axiomatically conservative based on face flux integrals. FEM is defined as a minimization problem--find the solution that best reduces the Galerkin (or Least-Squares) residual of this system. For solid mechanics, that minimization statement makes a lot of sense--configuration of solid mechanical systems map nicely to variational formulations. Conservation equations, however, do not.

For simple flow physics, the
...
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A note for CFD developers and the Spalart-Allmaras model

Posted June 12, 2021 at 13:06 by sbaffini (NuTBox)
Updated June 3, 2022 at 06:44 by sbaffini

This is a pretty specific issue which relates to my experience working on wall functions and the Spalart-Allmaras model, but might be useful to others or, more importantly, the users of their code.

If you followed my previous posts here, you know I developed a wall function formulation based on the Musker wall function which, thanks to a math trick, is integrable also for arbitrary Pr/Pr_t (Sc/Sc_t) numbers and also for some forms of non equilibrium terms.

One of the...
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OpenFOAM tips and tricks

Posted March 16, 2021 at 01:44 by sphani4391

I am sharing a few tips and tricks for better OpenFOAM simulations. These are not any new tips I discovered. These are just some which I felt most useful based on my experience.

1. Mesh is the most important aspect - I have spent countless hours fixing issues in other places while the real issue was with my mesh. As a thumb rule, make sure the mesh has: no non-orthogonality issues, low aspect ratio cells, no refinement zones in the region with high gradients

2. Always start...
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Boundary conditions for multiphase flow

Posted March 16, 2021 at 01:21 by sphani4391

I have struggled a lot with boundary conditions for multiphase flow, particularly where the multiphase spray is impinging on the outlet patch (typically the case of an internal flow simulation of a fuel injector spray). I have finally settled on the following Boundary conditions which work!

Simulation details: I am doing a 2D axisymmetric flow simulation using a wedge BC at front/ back planes. I am using a custom solver based on homogeneous relaxation model. This is similar to cavitatingFoam...
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Rating: 2 votes, 5.00 average.

Turbomachinery Solver OpenFOAM

Posted January 13, 2021 at 12:03 by badpuppet
Updated January 15, 2021 at 13:27 by badpuppet

Turbomachinery Solver OpenFOAM


This forum has been a big source of information for me since I started doing CFD. Now, I want to share my work to thank your altruistic knowledge sharing. Regarding the main topic of this blog, I am going to talk about my first turbomachinery simulations with rhoSimpleFoam, the problems I found with this solver and my solution, which I called turboSimpleFoam. Feel free to ask me whatever you want or tell me if something is wrong.

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