FLOWNEX – SYSTEMS CFD SOFTWARE FOR THE DESIGN, ANALYSIS AND OPTIMIZATION OF FLUID FLOW SYSTEMS
Flownex is used in the design, analysis and optimization of complete thermal-fluid systems. These systems range from simple systems such as cooling water systems and fuel feed systems to complex systems such as complete conventional or nuclear power plants. The ability to model the complete integrated system gives engineers the capability to quickly and accurately size components, do flow balancing and test different control methodologies in real time. Standard components with different levels of complexity are linked together in an arbitrary way to build any flow system. This is facilitated through an easy-to-use graphical user interface and the results are presented in a powerful graphical output. Distinguishing features of Flownex are: The solver is optimized for steady-state and dynamic problems A variety of fluid models including single phase and two-phase fluids Able to solve very large networks Exceptional speed of execution Capable of coupling with 3D CFD code, e.g. for including boiler combustion simulations EASILY PERFORM CONCEPTUAL DESIGN OF FLOW SYSTEMS Several conceptual designs can be evaluated easily and quickly by connecting the flow components in different configurations and observing the effect on the system pressure, temperature and mass flow distribution. Components such as pumps, compressors, turbines can also easily be sized and matched in order to obtain the most cost effective and efficient system layout. Flownex also features a designer functionality where automatic calculation of component sizes and capacities are possible to obtain a specified system operating condition. For instance to determine the orifice sizes for flow balancing in a system or determining the shaft speed or turbine guide vane angle in a power matched turbo-unit. SAVE TIME AND MONEY BY QUICKLY PERFORMING SEVERAL WHAT-IF STUDIES ON SYSTEMS Flownex allows engineers to perform real time investigations on systems to determine, for instance, what happens if: Valves are opened or closed in different parts of the system (phenomena like choking or the water hammer effect are also simulated) A pipe break occurs somewhere in the system The generator connected to the turbine is suddenly disconnected from the grid The boiler temperature or reactor reactivity is increased or decreased Knowing the system response to various events allows engineers to test different control methodologies. Flownex features a controller model and also interface to external control software such as Matlab, Simulink and UNAC. IT’S IN THE DETAILS Flownex’s implicit solution algorithm is fast, accurate and robust and resembles that of a conventional CFD code. The system is discretized into a number of spatial or conceptual control volumes to which a set of conservation equations are applied and then solved. This fundamental approach allows the prediction of phenomena such as choking, pressure surging, natural convection, Joule heating and buoyancy effects in packed beds. Flownex uses nodes and elements to represent a thermal-fluid network graphically. Elements are components such as pipes, pumps, valves, compressors or heat exchangers, while nodes are the end points of elements.  Elements can be connected in any arbitrary way at common nodes to form a network.  Flownex solves the momentum equation in each element and the continuity and energy equation at each node. Although components may be represented on the systems level as a single entity they may in actual fact be complex sub-networks. The main network with embedded sub-networks is treated as one large network in the solution algorithm. SUPPORT AND TRAINING Each sale of Flownex is backed by extensive training and support so that the allocated resources are ready to produce real solutions. CONTACT Flownex International: info@flownex.com Regional offices - Visit our website: www.flownex.com	Flownex model of a reticulation system with check valves in some pipes and pressure and mass flow as outlet boundary specification Flownex model of a two-shaft high temperature gas cooled reactor nuclear power plant. Example of the results of a dynamic simulation of the start-up of the gas cooled reactor power plant. The movement of the operating point on the compressor maps is also shown. Flownex model of a passive reactor cavity cooling system relying on buoyancy driven flow. Model includes conduction, convection and radiation between pipes and reactor. Flownex is developed within the ISO9001 framework and is extensively validated and verified. Here is a comparison of a recuperator response comparison to experiment with a transient pressure and temperature boundary variation. The thermal inertia of fluid and thermal capacitance of the solid material is included.