CFD ANALYSIS CHALLENGES IN BUILDING SIMULATION FOR SIMBUILD2004 CONFERENCE

This paper discusses the capabilities and challenges of computational fluid dynamic analysis (CFD) in the architectural engineering field. It is intended to provide a user's perspective of CFD challenges and not a scientific report on cutting edge simulation techniques and algorithms. The combination of large dimensions with often non orthogonal geometry poses a unique challenge to CFD software. Models quickly become very large and require more memory than some operating systems and workstations can provide. In addition to these model size issues architectural models need to properly consider ambient weather conditions. Solar loading and the resulting buoyancy driven convection can completely change airflow patterns and comfort conditions in a building. Equally important is proper consideration of exterior wind pressure on building openings. Methods for determining these and other boundary conditions are discussed. Changing weather conditions throughout the year require CFD analysis for several days of the year. Some problems cannot be solved in steady-state mode and require a transient analysis. Economic and project time limitations in the real world demand smart problem simplifications. A variety of methods for simplifying CFD problems without compromiing the validity of results are discussed