velocity becomes nan after few steps when initial velocity set to 0.2

[Comma0103]

I set the initial inlet velocity of Karman Vortex Street to 0.2, and kept other configs as below:

lbm = lbm_solver(
            "Karman Vortex Street",
            801,
            201,
            0.01,
            [0, 0, 1, 0],
            [[0.2, 0.0], [0.0, 0.0], [0.0, 0.0], [0.0, 0.0]],
            1,
            [160.0, 100.0, 20.0])

Then I ran it by python lbm_solver.py, but got velocity and vorticity nan after first few steps:

Is this an internal problem of the solver? How can I make it more robust? Thanks.

[hietwll]

increasing the inlet velocity leads to a larger Re number. to perform a stable simulation, you need to increase the grid resolution and decrease the time step.