A Critical Warning message in AFT Impulse.

This Critical Warning is followed by a list of all pipe stations with Vapor Volumes greater than 100% of the liquid volume, shown in the format: Pipe X, Stations: Y (Z%).

Vapor volumes larger than the total volume in the pipe section are physically unrealistic and indicate that full column separation and extensive transient cavitation are likely occurring in the system at that point. In this situation, the cavitation models are no longer physically meaningful, and the conditions in the model may be outside of the single-phase assumption that Impulse is based on.

Users should explore the various cavitation topics - and in particular the Interpreting Cavitation Predictions topic - listed below in the Related Topics section to better understand what is causing these results, why they are possible, and how to interpret results in scenarios with this warning. If all else fails, users should treat systems with these results with extreme caution.