Representation of Measured Ejector Characteristics by Simple Eulerian Bond Graph Models

Abstract

Ejectors (or jet pumps) are highly reliable pure fluidic devices very commonly used in power plants, propulsion systems, petrochemical processes and other thermofluid systems. However, little off-design data has been available in a form suitable for dynamic simulation and control system design. Fortunately, concerns of the nuclear industry have recently led the Idaho National Engineering Laboratory (INEL) to obtain, from their LOFT Test Support facility, ejector test data sufficiently extensive to formulate a complete model accurately describing all flow conditions. Thus an elementary fixed-constant bond graph structure will approximate complete ejector characteristics, while a model only slightly more complex fits all INEL data within experimental scatter.