turbulent viscosity
 

hei, i am simulating a two-phase flow of air-water in a circular pipe and after som iterations it stops and the following is shwon,

turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 9854 cells...

Error: Too many (0) VOF sub-timesteps. The velocity field is probably diverging. Please check the solution, and reduce the time-step if necessary.

I have reduced the time steps without any result, can anybody tell me what is wrong?

Thanks

Re: turbulent viscosity
 

what is the turbulence model ur using? What is the initial values of K and Epsilon(in case ur using K-E)?

That comment about TV limited ... means that ur Turbulence model is not working properly. Try initial values of K and Epsilon of the order of 10E-3 or 10E-4

I think that shud help ur case. Let me know if u try this?

Pardeep

Re: turbulent viscosity
 

U r getting message that turbulent viscosity is limited to 1.00e10+05. that mean calculated ratio is more than this..since it is limited to above value u r facing the problem... In fluent

goto SOLVE....CONTROLS.....LIMITS .. in limits increase the maximum turbulent viscosity ratio to 1.0e10+07 and try

best luck next time!

Re: turbulent viscosity
 

I am also getting same messege. May you tell me the formula to calculate turbulent viscosity. Thanks

Re: turbulent viscosity
 

The turbulent viscosity ratio is defined as following: turbulent viscosity --------------------- laminar viscosity

Re: turbulent viscosity
 

how about makign the grid little refined!!!!

Re: turbulent viscosity
 

is your problem still existing or did some changes make your simulation working again?

regards,

zachi