A Caution message in AFT xStream

Full Message text is:

The maximum transient pipe Mach number is at least X higher than the steady pipe mach number at the same location. If sectioning was determined from MOC steady results, the accuracy of the transient simulation may not be sufficient for higher flow periods.

 

This is a cautionary notice that there was a large change in Mach number between the steady state and transient results. The sectioning for the model is chosen based on the steady state results, and will therefore produce the highest accuracy results for cases where the velocity is similar to the steady state velocity. The inaccuracy due to sectioning is discussed further in the Transient Result Accuracy topic.

It is recommended to run the model again with more sections to determine what effect the Mach number difference has on accuracy.