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.

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.

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.

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.

hi akshay,

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

[Zoha]

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