[yangpeisi]

dear all
I am trying to simulate water flow through vertical slot fishway by means of VOF model while it can’t get convergent after numbers of try. Could anyone give me some suggestions about the project?More details are shown as follow.
Problem Description:
A part of fishway is choosen to be simulate as shown. The measure of the fishway is 16.8m(long)×3.0m(width)×1.2m(height) and the water depth is 0.9m.Water flow into the inlet of the fishway with a constant velocity of 1m/s. The top of the fishway is free surface.
Mesh
In ansys fluent’s report quality ,the maximum ortho skew is 1.50998e-01 and the minmum orthogonal quality is 8.49002e-o1.I wonder if the minmum orthogonal quality is unreasonable but have no idea how to improve it. I am a new ICEM user ,could anyone please give me some suggestions?
solver type : pressure-based time : transient
gravity Gravitational Acceleration x:0 y:0 z:-9.81
Model
Multiphase
Model Volume of Fluid
Number of eulerian phases:2
VOF Sub-model : turn on open channel flow
Volume fraction paramennts formulation: implicit
Body force formulation : turn on implicit body force
Viscous Model : k-epsilon k-epsilon model :RNG
Primary phase: air Secondary phase ：water
Turn on specified operation density : operating density :1.225
Inlet conditions pressure-inlet
Momentum
Turbulent intensity :5
Turbulent viscosity ratio :10
Multiphase
Turn on open channel
Free surface level :0.9
Velocity magnitude:1
Bottom level:0
Outlet conditions Type pressure-out
Momentum
Turbulent intensity :5
Turbulent viscosity ratio :10
Upper conditions pressure-inlet
Momentum
Turbulent intensity :5
Turbulent viscosity ratio :10
Solution methods Scheme PISO
Momentum second order upwind
Turbulent kinetic energy : second order upwind
Turbulent dissipation rate : second order upwind
Transient formulation : second order upwind
Region adaption
Input coordinates
X min :-4 X max :12.8
Y min :0 Y max : 3
Z min : 0 Z max :0.9
Then mark, others default
Initialization method : hybrid Initialization
Time step size : 0.01s Number of time steps : 3000


thanks