On Computational Fluid Dynamics Tools in Architectural Design

In spite of being apparently easy to use, computational fluid dynamics (CFD) based tools require specialist knowledge for modeling as well as for the interpretation of results. This point of view implies also that users of CFD based tools have to be carefully choosing and using them. Especially when many existing types of CFD based tools are developed for different purposes but for a user with lack of skills they can seem to be equal and faciliate inappropriate applications. This issue has initiated the present paper where two different types of CFD tools have been explored. A traditional engineering computational fluid dynamics (CFD) simulation program ANSYS CFX and a CFD based representative program RealFlow are investigated. These two programs represent two types of CFD based tools available for use during phases of an architectural design process. However, as outlined in two case studies the durability of the two program types for simulation of flow is strongly depended of the purpose. One case presents results obtained with the programs with respect to the accuracy and physical behaviour of the flow. Another case deals with wind flow around a complex building design, the roof of the new Utzon Centre in Aalborg, Denmark. The obtained results show that detailed and accurate flow predictions can be obtained using a simulation tool like ANSYS CFX. On the other hand RealFlow provides satisfactory flow results for evaluation of a proposed building shape in an early phase of a design process or as a tool for flow based form inspiration in the conceptual phase.