Improved Simulation of Thermodynamic and Other Systems Using a New Graphical Interface

This paper is a synopsis of an 80-page work entitled The THERMOSIM® Package for Simulating Thermodynamic, Hydraulic and Other Engineering Systems, A Users’ Manual[1]. This package employs a new user-friendly graphical interface to help model and simulate a wide variety of engineering and physical systems. It employs several thousand lines of code. Its primary focus, for which it has no bond-graph based competitors to the author’s knowledge, is thermodynamic systems with accurately treated flowing compressible and multiphase fluids. Thermodynamic data is included for 40 different fluids in a form that minimizes the need for iteration. Nevertheless, mechanical, electrical and hydraulic systems also are treated, as are compliances defined by their stored energy. Standard bond graph elements are employed where applicable, and the extended convection bond graph elements are used to represent concisely elements with complex thermodynamic properties of fluid flow, automatically enforcing the second as well as the first law of thermodynamics. The longer work employs 16 different examples in some detail; this synopsis is restricted to two: a piston-cylinder air compressor charging a tank and driving a load, and a hydraulic system with piston pump and actuator.