Bjørnar Svingen

Transient hydraulics simulations using component sub-vis in LabVIEW

Transient simulations of hydraulic piping systems consists of simultaneous solution of the 1D wave equations that relates flow to pressure in a pipe, and solutions of all other non-pipe components constituting the total system. The method of characteristics MOC is the most widely used method due to its analytic accuracy and speed. This paper present an implementation of MOC as a so-called toolkit or library in LabVIEW. Each type of physical component pipe, valve etc is programmed as a component sub-vi component sub virtual instrument. A component sub-vi can best be described as a lightweight variation of an object in an object oriented programming language, because data and procedures are encapsulated within each component. Hydraulic systems, with virtually limitless complexity, are then constructed intuitively using point and click methods in the standard LabVIEW interface, and later run, without needing any prior knowledge of LabVIEW. The modularity means that new components and upgraded components are easy to incorporate, while the LabVIEW interface provides all interactive graphical representation, both in batch mode and in real-time simulations. This toolkit is implemented in a package called LVTrans LabVIEW Transient Simulations. This package is actively used and under continuous development at SINTEF Energy Research, and is also licensed to Statkraft ASA.