Implementation of the Fluid Equations into Component Models

This chapter introduces the notion of staggered grid scheme and explains how it can be used to implement the thermal hydraulics equations into component models. The staggered grid is made of two superimposed grids, the first implementing the mass and energy balance equations, and the second implementing the momentum balance equations. Components from each grid are then connected together via so-called connectors. Connections are made according to well defined rules in order to exchange the variables common to different balance equations so that the full state of the system can be computed. Several alternatives are possible for the structure of the connectors. The fundamental choices made for the structure of ThermoSysPro are given.