Geometrical and topological issues for coupling dimensionally reduced multizone models with high-resolution CFD techniques

In this paper we emphasize a technique based on graph theory that allows for deriving both a dimensionally reduced object model required for setting up a thermal multizone model and a geometrical model for defining a single or multiple CFD domains in a building model together with incidence matrices correlating these models. The incidence matrices are an essential precondition for establishing a runtime coupling between both approaches such as automatically providing a CFD model with boundary conditions obtained during a thermal multizone simulation and vice versa. We thereby start from a CAD or a building product model. The algorithm is basically applicable to any building energy simulation tool.