The CFD0 Editor software enables you to define and view a CFD domain for detailed airflow and contaminant transport analysis. You can use it to define a CFD domain for either internal-zone or external-zone coupling with an associated multizone CONTAM model, or to define a stand-alone CFD domain for separate analysis with the zero-equation computational fluid dynamics software CFD0 that is provided along with the CFD0 Editor. CFD0 Editor provides for the definition of the domain, grid and boundary conditions and also allows you to view simulation results within a three-dimensional representation of the domain.
NIST Multizone Modeling Website 
