ESDU 78001 gives two methods of estimating this component of pressure loss and gives a guidance graph enabling the most appropriate method to be selected depending on the qualities of the inlet and outlet flows. The effects of pressure gradient and heat transfer on flow equilibrium are discussed. ESDU 76018 and ESDU 77016 give methods for predicting the frictional and gravity components of pressure loss and ESDU 78018 gives guidance on using this group of data with practical worked examples.
ESDU 78001 A-2007 history
2007ESDU 78001 A-2007 The momentum-change component of pressure change in two-phase flow and other non-equilibrium effects.