Water drop falling too slow - Interfoam
I wanted to sim the falling of a drop into water. Nothing complicated (!), I just followed the dam tutorial.
The problem is that the drop is falling too slow (from steady: 50mm in 1.2s) and the velocity is not increasing.
Please see enclosed pictures about alpha and U.
Here is checkmesh result:
The water is a sphere with radius=8mm.
Flow is laminar.
g is defined as:
The sim is running without any problem. Courant Number is well respected and residuals are ok.
It seems phase2 is too viscous...
I'm sure it's a silly mistake of mine but where ? Please be kind if you know it :o
Ok, it seems nobody is able to find the mistake ;)
In the meanwhile I enclose a video of the lazy drop
Nice to see the surface tension working when the drop is approching the water.
Any idea ?
Did you by any chances made the bottom patch as a wall? That's might be the only reason I can think of.
Thanks Duong !
In effect my problem is about boundaries.
I meshed the domain using my normal routine: CAD + blockMesh + SnappyHexMesh.
This is usually perfect for "complex" geometries but not in this case.
I don't know why but it seems SHM has problems when you try to mesh a box using another blockMesh-defined box with the same dimensions... it calculates the right mesh but with some missing boundaries.
Could I see the mistake before ? Yes, sure. See the checkmesh result I posted before:
Why haven't I used blockMesh only to mesh such a simple case ? Well, I already have my habits...I'm lazy :p
Anyway a good lesson... read carefull everything !
Thanks again Duong to show me the light :)
Well, another question would be: "How can some messing BC reduce the velocity of a falling drop without blowing out a simulation ?"
But this is out of my reach so far...
setting 2D sphere
My point is how to set a sphere using only setFields, i am planning to modify the dam break in interFoam to simulate a falling drop in solid surface a time and over a liquid as here the other time..
after that, how to assign proper boundary condition to the falling droplet?
moreover, shall i asign an initial velocity? i am assuming it falls freely under gravity effects and starts from say, 0 m/s
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