Learning Forum

[Amir]

Hi everyone,

I am going to simulate a droplet on a surface, the droplet is expected to evaporate,

I defined an animation of the volume fraction of the liquid, to see the droplet interface I used this setup

which give me such animation

0)is my way correct?

I wonder if you could help me on these questions

1) for monitoring the top location of the droplet which is in the y direction on the zx surface (gravity in -y direction is) is this expression correct?

Maximum(IF(Volumefraction(phase='liquid')>0.5, y, 0 [m]), ['fluid'])

2)to monitor the total area that the droplet wets is this expression correct?

AreaInt(IF(Volumefraction(phase='liquid')>0, 1, 0), ['wall']))?

3) I would like to see the total perimeter of the interface in the above picture (the red curve), and monitor it all over the simulation, would you please tell me what its expression is?

I could not find any way for that

thank you in advance

[Rob]

If the expressions return the values you expect then yes, they're correct. I don't have examples to check against. The approach is sensible. 

The circumference may be a little difficult to get. As the solver works on node values you're always interpolating to see a curve. With a very fine mesh the error will be small. Similarly if you have a polar type mesh the interpolation will be reduced. If you create an isosurface of VOF but select the wall  surface you'll (probably) finish up with a line. Reports of min/max for mesh may help, and you may be able to plot an xy graph for x-versus-z ?