Setting relaxation lower than relative pressure/flow tolerance gives unreliable results

A Critical Warning message in AFT Fathom

Because of the nature of relaxation and relative solution tolerance, setting the relaxation to a value close to or lower than relative tolerance can lead to false convergence and invalid results. AFT Fathom alerts the user to this when inputting data in the Tolerance panel or Iterations panel in the Analysis Setup window, and also alerts the user once the solution has been obtained.