Hello, I am quite new in OpenFOAM, and very new wi...
# general-helpc
c.adiningrum
09/30/2026, 8:04 AMHello, I am quite new in OpenFOAM, and very new with Discord.
Apologies if this is not the right place, or not the right way to ask question.
I am trying to do some simulation, which I previously wrote in
https://www.cfd-online.com/Forums/openfoam/263081-openfoam-2512-pimplefoam-les-compound-channel-secondary-current-not-appearing.html
I am copying it here, hoping it will reach more people.
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I am trying to reproduce a case from De Silva & Tanaka, "Study on Sedimentation and Turbulent Flow Structure in Compound Water Channels with Vegetated Floodplain" (ISRS2013), but without vegetation for now.
The paper reports:
1. Higher velocity on the surface above the main channel compared to the floodplain.
2. A secondary-flow at the main-channel/floodplain interface.
My goal is to find out the configuration which can reproduce similar results, and also see the vortex pattern on the surface. Ideally, I am trying to create a setup which I can run once and reliably see both the secondary current and the horizontal vortices, instead of running separate simulations to see the two.
My setup:
1. Solver: pimpleFoam. Free surface treated as a closed rigid lid, the top patch uses type slip in 0/U.
2. Turbulence: simulationType LES with LESModel kEqn.
3. 60s simulation
Mesh:
1. Base resolution: 1 cm (background block from blockMesh).
2. Use wall functions: nutURoughWallFunction (rough-wall log-law) on relevant walls, targeting y+ 30 to 300.
3. Surface refinement: level 1 near walls and atmosphere, roughly 5 mm cells within 25 mm the surfaces
4. Cell count: 3,716,632 total (220,280 at level 0, and 3,496,352 at level 1).
y+ example:
Copy code
yPlus yPlus write:
writing field yPlus
patch channel_base y+ : min = 4.52595, max = 80.9343, average = 34.5032
patch wooden_walls y+ : min = 6.75966, max = 74.4809, average = 34.2811
patch glass_walls y+ : min = 19.0748, max = 170.741, average = 60.65912 Views