3D Flow over a circular cylinder
 

hi, i am using FLUENT 6.1 to solve 3D flow over a circular cylinder in unbounded domain.i could validate drag(CD) and St for unsteady flow past a circular cylinder in 2D. But in my 3D calculations, the drag values for Re =100,200,300 are coming to be higher if i use a boundary layer on cylinder and lower if i dont use a Blayer. What could be the fault in my computations using FLUENT ??? please suggest me the efficient way to use FLUENT for 3D computations.

Re: 3D Flow over a circular cylinder
 

What do you mean boundary layer on cylinder?

Re: 3D Flow over a circular cylinder
 

i attached boundary layer on the cylinder surface using the option available in Gambit

Re: 3D Flow over a circular cylinder
 

well i have also observed such behaviour that if i use prism meshes near the walls of cylinder i get higher CD and if i am using tet meshes (i am using LES as model) i get better CD values (by better i mean close to experimental values). i am not able to figure out why. but i have observed that if i use ke-realisable with prism meshes near walls the results are close to experiments but then with k-e-realisable and tet meshes near wall the CD values are low.