Validation of Grasshopper-based Fast Fluid Dynamics for Air Flow around Buildings in Early Design Stage

Abstract

This paper presents an implementation of a custom Fast Fluid Dynamics (FFD) code in Rhinoceros and its visual programming platform Grasshopper for studying airflow around buildings and related surface pressures. The advantage over conventional CFD is significantly faster computing time. Hence, it enables the consideration of airflow during the conceptual design phase and for use with computational optimization methodologies. We validate our implementation with different experimental and numeric studies. The results show a good match for velocity and pressure distribution with simple cases and a reasonable match for a large-scale urban case. Furthermore, we show the significant impact of an exemplary urban context on resulting surface wind pressure coefficients of a building. The CAD integrated FFD implementation presented in this study enables the consideration of airflow on early design decisions or in optimization design methodologies in a time-effective manner.