vof_model_grid refinement _urgent plz help
 

Dear all,

I am facing a great issue regarding simulating a rotating cylinder using vof method. I did for 6 different grid sizes for a domain of size 8cm*2cm. THe different no of cells taken are 1600,2560,6400,10000,25600,40000 for this domain size . I observe that the last two finest grids give me very different velocity profiles as compared to other grids, also i think its not realistic , i am not able to make out wats the issue bcoz as we go on refining the grid size the solution shud converge which is not happening.

i will be highly obliged if u kindly help me in resolving this issue , i need it urgently.

regards garima

Re: vof_model_grid refinement _urgent plz help
 

what you want to study from this case?

Re: vof_model_grid refinement _urgent plz help
 

i WANT TO STUDY VELOCITY PROFILES

Re: vof_model_grid refinement _urgent plz help
 

I mean do u have air-water flow or what type of flow regime you working with?

Re: vof_model_grid refinement _urgent plz help
 

yes i AM TAKING an axisymmetric swirl case . my geometry consistes of a axisymmetric cylinder 8cm*2cm. the height of the cylinder is 8 cm and the radius is 2 cm.the cylinder is filled with water till a ht of 3 cm , the rest is air. at the top of the cylinder i hav taken pressure outlet boundary condition and the wall is rotaing at speed of 50 rad/sec. if u want i can send u cas n data file at ur id, but u need to send me ur id for that

Re: vof_model_grid refinement _urgent plz help
 

There may be several reason for not converging your solution, one may be turbulance modeling. Anyways which model you are using for Turbulance?

Re: vof_model_grid refinement _urgent plz help
 

Dear Sir,

I am not involving any turbulence model bcoz the rotaional speed is 50rad/sec and hence its being assumed that there is no turbulence. can u plz help in this issue