[stefenbink]

hi, in my case, I want to fill the tub until it is full with water in 2D. if I use time step size low = 0,1; number of time step = 100; auto save every(time step) = 10

i need time until 60 s, until the tub is full but in interation (before the tub is full) i got error message in 2 s, . the tub is not full yet

what things should i change?


ps: error "Global courant number is greater than 250.00 The
velocity field is probably diverging. Please check the solution
and reduce the time-step if necessary."


thanks alot, if you can help me, this now.

global courant number.jpg

[stefenbink]

please any one can help me.. i will be very grateful to you

[taxalian]

Hi,
Well i think you are using a larger time step, so try running with a smaller time step in combination with more inner iterations. Save the solution at each time step. How did you selected your current time step? I would calculate the local timestep using the relation Time = Distance / Velocity, that would be in your case the height of the water level to achieve and the water flow velocity.

Originally Posted by stefenbink

hi, in my case, I want to fill the tub until it is full with water in 2D. if I use time step size low = 0,1; number of time step = 100; auto save every(time step) = 10

i need time until 60 s, until the tub is full but in interation (before the tub is full) i got error message in 2 s, . the tub is not full yet

what things should i change?


ps: error "Global courant number is greater than 250.00 The
velocity field is probably diverging. Please check the solution
and reduce the time-step if necessary."


thanks alot, if you can help me, this now.

Attachment 27667

[stefenbink]

thank you so much, has reply me

Originally Posted by taxalian

Hi,
so try running with a smaller time step in combination with more inner iterations. Save the solution at each time step.

so what is the good combination of time step for this case,?

now i set time step size low = 0,01; number of time step = 100; auto save every(time step) = 5 and iteration = 200. is it good combination?

Originally Posted by taxalian

How did you selected your current time step?,

i'm sorry, i don't know how. i just use default setting, and set the time like i said before.

Originally Posted by taxalian

I would calculate the local timestep using the relation Time = Distance / Velocity

and i don't know too, how calculate the local timestep using the relation Time = Distance / Velocity?
i select it from "calculation activities" or "monitors"? please explain to me

thanks so much

[stefenbink]

taxalian, i've solved the problem now,
thank you so much