[CaraH]

I am modelling a supersonic wind tunnel to simulate shock trains and measure the axial pressure distribution. When using a coarse mesh, the simulations converge. However, as it becomes more refined I get a floating point error: overflow. I have tried using temporary storage retained and running it for one iteration to check for convergence, but as soon as it is refined enough the error returns.

[me3840]

Please post images of your case and list the BCs you're using.

Are you using the coupled solver's grid sequencing initialization?

[CaraH]

The boundaries are set as stagnation inlet and pressure outlet, relative to atmospheric pressure.
I am unfamiliar with grid sequencing initialisation but will look into this and try it out, thank you!