Hi all,

I am a graduate student from Bengal Engineering and Science University, W.B., India currently working with Fluent 6.2 in trying to model vegetated open channels. In this regard I am facing some problem related to open channel boundary conditions in VOF model in Fluent.

My questions are 1) How to specify different boundary conditions in open channel simulations? 2) Is it appropriate to select two phase model in case of open channel(if so then how to specify air and water inlet BC saperately)? 3) If i select only one phase(i.e., water) what should be outlet boundary condition (as in case of open channel outlet pressure will not be atmospheric pressure, then what should be it's boundary condition)?

I request you to provide your valuable suggestion on what boundary conditions are appropriate at the inlet, outlet and upper surface in Fluent. I am currently using two phase model (air phase at the upper portion and water phase at lower portion).

waiting for your response.

Biswanath Mahato

hi Mahato

use two inlets, top one for air and botom one for water. in operating conditions make sure teh pressure acts in the air inlet region. i suggest u use water as primary phase, for top inlet conditions specify primary phase (water if u select water as primary) volume fraction as 0 and for botom intet conditions use secondory phase (air) as 0. have a single outlet and bc can be pr.outlet or simply outlet. i hope my suggesion is helpful. Regards Rizwan.