A Critical Warning message in AFT xStream alerts users to serious issues in the model results. These messages should always be reviewed by the user, and results containing these messages should never be used for anything other than error resolution purposes.

CRITICAL WARNINGS

• Characteristic speed exceeded maximum determined from...

• Global energy balance disabled

• Global mass balance disabled

• Junction X Had Reverse Flow - Compressor/Fan Head Could Not Be Predicted

• Maximum transient pipe Mach number X higher than estimate Y

• Pipe Mach number exceeded 1 during the simulation.

• Results do not represent a converged solution

• Required flow to supply the pressure control valve at junction X is above sonic flow

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

• Specified flow through/out of junction X is above sonic flow and cannot be supplied