Modelling gas turbine systems for transient performance using bond graphs

A progressive advancement in marine transportation is just taking place based upon an increased demand for hi-fi speed light crafts with narrow hull design forms. Primary considerations for the propulsion system is performance, weight and reliability. Gas turbines has therefore been considered as a potential option for such applications. This has also brought forward a need for quantitatively evaluation of the propulsion systems operating conditions. To perform such evaluations mathematical models must be available. In this paper a set of basic models for gas turbine system modelling is developed using the bond graph method as a framework for both model representation and as the unifying modelling methodology. Utilizing the component models developed a complete gas turbine propulsion system is simulated during large transient loads resulting from air entrainment in the propulsor at heavy sea. The objective is to study the behavior and thermal loading on the turbine under such conditions.