Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Incompressible and isotropic Newtonian fluid water film flowing downwards on a wall with a horizontal obstacle

Please login with a confirmed email address before reporting spam

HI, I am trying to model a water film that flows downwards on a wall surface and then hits a horizontal obstacle to change direction. For the boundary conditions: The water fim has a inlet velocity of -0.13 m/s in y-direction and 0 in x-dir, and 0 in pressure. At the outlet, it has a velocity of d.1/d.2 * 0.13 m/s i x-dir and 0 i Y-dir and 0 pressure. D.1 and d.2 are the width of the film at inlet an outlet respectively. For the boundary between the waterfilm and the wall, there is no slip and no velocity in x and y-drections. For the boundary between the water film and the ambient air: exposed to the external air pressure (p=0) (open ”Gortex-like” membrane that holds the water in place but has no friction.) The water film can take no shear stresses. To be known : pressure distribution in corner area, where the water film change direction. I have a very simple model now but I do not feel that it is the correct one. ma main question is about how to define the boundary condition between the water film and the ambient air, as described obove. Any suggestions ? (For a more proper description, please take a look at the ppt attached.)

Thanks in advance! Best regards Ali



0 Replies Last Post 24.11.2018, 05:56 GMT-5
COMSOL Moderator

Hello Ali Naman Karim

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.