[tangd]

I used the mesh in forwardStep, and applied my own boundary condition, it's running pretty well. But when I introduced another mesh, say pitzDaily from coodles with the same boundary condition setting. Then it shows:

Starting time loop

Time = 0.002

Mean and max Courant Numbers = nan nan
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
BICCG: Solving for Ux: solution singularity
BICCG: Solving for Uy: solution singularity
BICCG: Solving for Uz: solution singularity
BICCG: Solving for e: solution singularity
BICCG: Solving for p: solution singularity
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = nan, global = nan, cumulative = nan
BICCG: Solving for p: solution singularity
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = nan, global = nan, cumulative = nan
ExecutionTime = 66.33 s ClockTime = 66 s

I tried to use different value of deltaT, but it doesn't help. Wondering why the courant number is nan. Welcome any help. Thanks!