vortex formation past 4 cuboid bodies
 

hi,
i am trying to obtain vortex around 4 cuboid bodiesin zigzag pattern in 3d fluent using large eddy simulation. but cant get any vortex. each cuboid has length and width of 40m and height 150m. re no is 100. i am using air as the fluid.
boundary conditions are at inlet: velocity inlet vx=.98m/s
outlet : pressure outlet
building : wall
ground and sea: wall
side boundaries and sky: symmetry


i have uploaded a 2d image of my mesh in xy plane

i have given a link for my mesh.can anyone help me with getting vortex
thnx in advance


https://drive.google.com/file/d/0BzD...ew?usp=sharing