Mesh Independent Test
 

Hello all, I am attempting to run simulations in Fluent for a mesh that I generated in ICEM. The geometry is a pipe inlet into a vertical cylinder, which fills up and then exits out of another pipe. I have imported the initial coarse mesh and I have run a simulation. I now would like to perform a mesh independent test and I am having a few questions.

1.) I would like to do a global comparison test for my different mesh refinements where I look at multiple velocity points throughout the volume with each refinement. How do I view velocity at certain points in the volume, and continue to do so with each refinement?

2.) I would like to compute the boundary layer thickness. Is the best way to do this to make a slice plane and plot the velocity contour, determining at what position approx. 99% of the free stream velocity is reached?

3.) When I run my simulation, the residuals are high. The velocity residuals only decrease to about 1e-2, whereas the continuity residual stay close to 1. Could this be because the solution is initialized close to the actual solution value? It still seems to me the velocity residuals should further decrease, so I'm not sure how to determine convergence

I've attached my geometry in case that would be helpful. Thanks for any feedback on the questions I'm having.

First of all please donate compare for velocity at single point in region. The results for such points are never homologous. Compare average velocity on certain plane instead or draw velocity profile along some line. And then compare these results

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For subsection 2.. I don't think residual order is dependent on initial conditions that much. Try to observe courant number. See the residual behavior for most refined mesh.

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