Engineering Assumptions

AFT Impulse is based on the following fundamental fluid mechanics assumptions:

• Liquid-phase flow only

• Entire system is wet (100% liquid full)

• AFT Impulse is not meant for analysis of two-phase flow

• One-dimensional flow

• Fluid properties remain constant during transient

• Non-condensable gas release and dissolution is negligible

• Wavespeed remains constant

• No chemical reactions

• Fluid density is not affected by pressure waves in the system

• Vapor pockets formed during transient cavitation in pipes are considered point-volumes at section boundaries and do not move

• AFT Impulse is limited in its ability to model sustained cavitation and two-phase flow. The accuracy of results will be reduced when sustained two-phase flow conditions exist. Small cavitation volumes over short durations are handled with good accuracy.

• Additional assumptions exist for particular modeling components and features, discussed where relevant