Hi all: I have a problem with the VOF model when I start iteration with my case I am not saw FLUENT draw the residual for the volume fraction for the secondary phase? That's mean the vof equation not solved can anyone tell me the reason for this? Knowing that I chose the option solve vof every iteration in the VOF panel?

Thanks a lot for any suggestions K. Baker

let the solver iterates, and you will see after any iterations, that the solver will also includes vof equation. I had similar "issue" while computing cavitation calculation. vof residuals appeared after few iterations.

No it not appear anymore. I not think the problem as you said because the results for vof not appear to me when I try to drow it a long the axial or radial distance a long the pipe such I have stratifed two phase (oil-water) flow , oil in the buttom and water in top and I was use the VOF model I am not familiar with caviation model.

Khalid

can u see two phases at initial conditions?(with countour->phases) do u have two phases at all? after some iterations does your model changes? see the vof tutorial 15 of fluent manual for more discriptions

Hi Mohsen thanks to the reply when I display the contours at initialize it give vof value same as to what I give at the inlet and no change will occur during the iteration for this value. I have two phase (oil-water) flow the water flow in the button of the pipe and oil in the top I consider water as secondary phase , at the inlet I use the BC velocity inlet I used only one inlet for both phases and I give mixture velocity with the vof value for water , at outlet I used the boundary pressure outlet with a default value of vof for water (0) . The results being reasonable for the velocity profile but no change happen for the vof of water and when I try to see the variation of vof along the radial direction in the xy plot nothing was appear to me? I have a paper similar to my case and its author also use the VOF model with FLUENT 6 and he get good results for vof values but I cannot? Did you have further suggestions to my problem?

Thanks so much K.Baker