About Brackbill's Continuum Surface Force (CSF) model
 

I am attempting to use Brackbill's Continuum Surface Force (CSF) model to simulate surface tension in a free-surface flow. For my simulation, the time step constraint imposed by the explicit treatment of surface tension is too tight. The allowable time step is up to the scale of 10^-9 second. Does anyone know any references which use an implicit treatment of surface tension under the framework of CSF? Thanks!

James

Csf
 

Hei James,

I also use the CSF method for free surface flow, but I don't experience such drastic constraints for the timestep. Maybe your code has an error. Depending on your formulation of your Navier-Stokes Equations, you may need to dived the surface tension source term by the density (or multiply with the volume, if you use the finite volume method).

Cheers Hans

valgrinda,
Thank you for your reply! I will double-check my code.

James

I noticed that in Brackbill's paper, the average density <Rho> = 0.5*(Rho1 + Rho2). In some other places, this density is taken as a volume averaged value. Which is way is good? Thanks!

James

CSF Implementation
 

Hei James,

check this paper for the implementation of the CSF model:
http://wissrech.ins.uni-bonn.de/rese...er/droplet.pdf

Regards
Hans