[ghouston]

Hi,
I am new to posting here, but I have been lurking for a bit. I am doing a project on swirling flow by rotating the bottom wall of a axial-semetric cylinder. I am using the rotatingWallVelocity BC for the bottom wall but I have a few questions.

1) I am using the icoFoam solver for the low Reynolds numbers but I am confused on how the dimensions are lining up. With rotatingWallVeloicty I define an "omega" for rotational velocity, so are the units icoFoam is using rad./s or a tangential velocity in m/s?

2) For the time step of the solver I must make sure the Co is below 1 for this solver. For the units to line up on Co the velocity must be in m/s but I am defining a rotational velocity, which do I use for Co?

Thanks for any help you can provide, I will keep looking though my text books.

[Ohbuchi]

Hi,

1) If you use movingRatatingWallVelocity, dimension of omega is rpm (=min-1).

2) How about using adjustTimeStep option and setting maxCo in your controlDict.