Positive Displacement Pump Modeling

[amptramp]

I am attempting a network analysis of a fuel oil delivery system. I am using a set of Q-equations (continuity equations and work-energy equations) to model the pipe network flow characteristics. The pump in the network is a triple screw pump. Although I understand how to model a centrifugal pump, e.g., AQ^2 + BQ + C with coefficients determined from pump curves, I am unsure how to model a positive displacement pump. The continuity equations are easily wriiten but the work-energy equations are troublesome as I am unsure how to incorporate the pd pump into the loop equation. Does anyone have a suggestion or a resource? Thanks!

 

[rbcoulter]

A PD pump is assumed to be a pump that will pump a constant flow rate at any pressure. This should be easier to model. Just set the branch where the PD pump is at to its constant flowrate. So the pump equation is Q = K, where K is the flowrate of the pump which is only a function of the pump configuration, RPM, etc. and not of the resistance of the piping network.