The foundational axioms of fluid fluid are the conservation laws specifically, conservation of mass, conservation of linear momentum (also known as Newton's Second Law of Motion), and conservation of energy (also known as First Law of Thermodynamics). For fluids which are sufficiently dense to be a continuum, and have relatively low velocities (relative to the speed of light), the momentum equations for Newtonian fluids are the Navier-Stokes equations, which is a non-linear set of differential equations that describes the flow of a fluid whose stress depends linearly on velocity gradients and pressure. At SimSci-Esscor we've focused on implementing a variety of empirical and mechanistic pressure drop models that solve simplified forms of the Navier-Stokes equations, for the purpose of modeling the movement of fluids through pipelines and process equipment.  

SimSci-Esscor develops & supports a range of 1-D Fluid Flow (hydaulic) simulators, both steady state and dynamic that model the flow of single phase and multiphase fluids throught wellbores, pipelines and processing facilities. Our simulators employ a physical property package, such as a thermodynamic equation of state, giving the pressure as a function of other thermodynamic variables for the fluid coupled with a pressure-flow algorithm which solves the mass, monentum and energy equations that describe the system. Unlike traditional process simulator such as PRO/II, where the user is required to fix flow rates for inlet streams, where the specification of vessel and piping geometry is optional and where process fluids can flow from a low pressure source to a high pressure sink, in a hydraulic simulator pressure regulates everything.