Pressure diverging problem during LES
 

I am trying LES with 0.0005s time step,

but pressure is diverging for some time steps.

Solution is not always diverging, and divergence occurs about once per 100 time step.

I checked velocity field, but velocity didn't divereged and only pressure had diverged to infinite or negative-infinite.

I tried LES with other mesh settings with finer meshes, but same problem occurred.

Does someone have any idea for reason or solution for this problem?

What drove you to that time step? Are you sure that your CFL number is appropriate? Knowing what you are trying to model would help. 'Trying LES' can mean a lot of things.