User Forum of Software BASEMENT

nicolagroff

User

Registered: 2017-08-07

Posts: 10

Problems with OUTFLOW BOUNDARY due to FRICTION

Hi!
I'm using BASEMENT 2.7 and I have the following problem: if I change only the Strickler friction parameter of the river bed from 30 to 27 m^(1/3)/s, in the simulation I have an unreal flux with high velocities (more than 200 m/s) that cames from the outflow boundary.
I'm using the outflow boundary condition of type zero_gradient.
If I run a simulation with the same mesh, the same boundary conditions, but a Strickler friction parameter of the river bed egual to 30 m^(1/3)/s, I do not have any problems.

How could I fix this problem?
Thanks for helping

Nicola

René Kaufmann

User

Registered: 2016-01-28

Posts: 22

Re: Problems with OUTFLOW BOUNDARY due to FRICTION

Hi Nicola

try the hqrelation as outflow boundary condition. To this boundary condition, you have to add a slope.

René