Patching
 

hi,

I want to patch a semicircle in a rectangular grid in a two-dimensional case. There is no option of patching a semicircle in fluent.

for example , suppose my rectangular grid is having coordinates as (0,0), (0,10),(30,10),(30,0) and i want to patch the semicircle at centre (0,1.5) and diameter of 3mm.

please reply soon...... its very important for my project.

Re: Patching
 

Your semicircle lye on the boundary face. So you can create this semicircle with a circle option,as the remaining semicircle will go outside the domain where there are no cells. This is not a problem.

In case if you have this semi circle inside the volume, you can create this facevolume initially in gambit and name it as a different fluid zone.

help
 

hi,

actually iam trying to simulate the dynamics of droplet impact over a flat plate . i have assumed that 1) drop has reached its terminal velocity before impact. 2) deformation of drop is neglected.

my domain is rectangular domain of 30 mm * 20 mm one boundary (Bottom horizontal) is wall rest all are open bounday , I have patched a circle in the middle just touching the wall. so, i have given a constant downward velocity to a patched region which is just over the wall.and included the interaction between the wall and the fluid is surface tension.

i did the simulation and found that after the drop has reached its maximum spread diameter , it starts retracting and the then the spread diameter reduces. its is taking larger time then the actual simulation. but is able to simulate it quiet nicely.

i want to know...... 1) what all have i included( forces) by doing following simulation

2) Have i included the effect of dynamic contact angle. if not..... how can i include it. 2) i want to change the properties of the wall means....roughness, wettability etc.

Re: help
 

You can include dynamic contact angle through a udf DEFINE_PROFILE. A hook for contact angle is available only in 6.3 and not in lower versions. When you select multiphase model, then go to define->phases, interaction and toggle ON wall adhesion. You will find contact angle in wall boundary condition. In wall boundary condition you can give roughness(and also attach a udf), this will be highlighted when you toggle ON some turbulence model. Wettability is not defined directly in fluent.

Re: help
 

hi akshay,

thanx for ur message. Can u give me a detailed information about inclution of contact angle through DEFINE_PROFILE.

Patch a semi Circle
 

Hi
I wanna patch a semi circle two
but in a different way

I need to patch a circular droplet which half of it is water and the other is oil. Would you please help me ASAP
thanks so much