Application of Bond Graph to Thermofluid Processes and Systems

Over the past few years a study was focused on development of bond graphs for thermofluid processes and systems using the true power variables of temperature and time rate of change of entropy. This paper summarizes the steps taken in this study. Discussion begins with study of a simple case of single phase incompressible flow and ends with a completely general case of multi-phase, variable density flow. Variations in density require introduction of momentum equation to the bond graph. Inclusion of entropy as a state variable necessitates formulation of Gibb´s equation and its representation by means of bond graphs. This paper presents these formulations and representations, and compares dynamic results predicted by bond graphs with classical approaches.