The Quasi-Propagatory Model (QPM), a new approach to simulate fluid transients in duct systems, is presented in this paper. The model fills the gap existing between lumped-parameter and distributed-parameter models, allowing the simulation of propagatory effects, even in a compact, lumped-parameter framework.
The model, previously developed for homentropic flows, is extended here to include the presence of section variations, friction and heat flows. This is done without substantially altering the model architecture.
A theoretical and an experimental validation of the QPM have been carried out. Test cases have been run and the results compared with those yielded by the Method of Characteristics, which was taken as a reference model. Moreover, the model predictions were also compared with experimental data measured in a pipe test rig.