Paper Conference

Proceedings of Building Simulation 2017: 15th Conference of IBPSA


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

Christoph Waibel1,2, Lukas Bystricky3, Aytaç Kubilay1,4, Ralph Evins2,5, Jan Carmeliet1,4
1Chair of Building Physics, ETH Zurich, Switzerland
2Urban Energy Systems Laboratory, Empa, Duebendorf, Switzerland
3Department of Scientific Computing, Florida State University, Tallahassee, USA
4Laboratory for Multiscale Studies in Building Physics, Empa, Duebendorf, Switzerland
5Energy Systems and Sustainable Cities Group, University of Victoria, Canada

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.
Pages: 2147 - 2156