Hi both,
For this run, first attempt to disable potentialfoam, then if still unstable, try using smooth solvers for all conditions (U, P, k, w). There should be no reason why higher order schemes are not usable, but if the sim continues to be unstable, change the gradient scheme to gauss linear for grad(U).
Similar comments for this.
It is important to get the sim running first before attempting higher order schemes or faster solvers.
Cheers.
Regards,
Barry