[florian_krause]

Hi guys and especially LES-pipe-flow-experts ;-)

On OF-1.6.x, I am using pisoFOAM with LES turbulence model to simulate a fully turbulent pipe flow with Re=7000 based on the centreline velocity.
The pipe is fully 3D and the dimensions are L (pipe length) =5*D (pipe diameter). My grid look attachment grid.jpg . I have 3 grid points in the viscous sublayer, whereas I I calculated the size of the viscous sublayer from the friction velocity calculated by a DNS for the same flow.

I performed now two different simulations (first one explained here, second one in the following post)

1.) I used cyclic boundaries on the inlet outlet pair and initialized the flow with a uniform flow field (flow in z-direction) and some reasonable turbulent kinetic energy k (corresponding to 10% turbulent intensity)

The problem is now, that my flow and my velocity profiles developes into Poseuille flow profile, but I have small amount of (z-)vorticity and turbulentt kinetic energy.

I attached the corresponding plots for Uz, k and z-vorticity plot and contour plot.

For the whole computation time, my courant number is below 0.5 so my timestep should be ok.

My LES SGS model is the oneEqnEddyViscosity model.

Do you guys have any clue how I could improve my setup for my boundary conditions ? My fvSolution and my fvScheme files are copied from the pisoFoam -> les -> pitzDaily case

...see next post....