Computational fluid dynamics (CFD) can provide high-resolution data for the peak pressure coefficients required for cladding design; however, use of CFD in the design process requires a careful balance between the computational cost and the accuracy of the numerical simulations. On one hand, Reynolds-averaged Navier-Stokes simulations (RANS) have a low computational cost, but the accuracy of the results can be significantly reduced by the Reynolds stress models and the need for additional empirical relationships to calculate peak pressure coefficients. On the other hand, large-eddy simulations (LES) come at a significant increase in the computational cost, but they can provide accurate predictions by resolving the larger energy-containing scales of turbulence. This presentation will discuss recent research on quantifying and improving the accuracy of CFD results for pressure loads on a high-rise building. The test case reproduces an experiment performed in the atmospheric boundary layer wind tunnel of the Politecnico di Milano, which provided high-resolution data on the lateral façade of a high-rise building for different wind directions. Uncertainty due to the inflow boundary conditions and the (subgrid) turbulence model has been investigated in both RANS and LES predictions. The results indicate that turbulence model uncertainty limits the use of RANS results for cladding design, while LES can provide predictions with confidence intervals that encompass the experimental data for the peak pressure coefficients. Since the computational cost of LES hinders practical use in the design process, we propose a data-driven multi-fidelity simulation technique that takes advantage of both the low computational cost of RANS and the improved accuracy of LES. Initial results indicate that the method can reduce the number of LES necessary for design, while maintaining acceptable accuracy in the prediction of the peak pressure coefficients.
Catherine Gorlé is an Assistant Professor of Civil and Environmental Engineering at Stanford University. Her research activities focus on the development of predictive computational fluid dynamics (CFD) simulations to support the design of sustainable buildings and cities. Specific topics of interest are: the coupling of large- and small-scale models and experiments to quantify uncertainties related to the variability of boundary conditions, the development of uncertainty quantification methods for low-fidelity models using high-fidelity data, and the use of data assimilation to improve CFD predictions. Catherine received her BSc (2002) and MSc (2005) degrees in Aerospace Engineering from the Delft University of Technology, and her PhD (2010) from the von Karman Institute for Fluid Dynamics in cooperation with the University of Antwerp. She has been the recipient of a Stanford Center for Turbulence Research Postdoctoral Fellowship (2010), a Pegasus Marie Curie Fellowship (2012), and an NSF CAREER award (2018).
Joachim Reuder is Professor in Experimental Meteorology at the Geophysical Institute and the Bergen Offshore Wind Centre (BOW) at the University of Bergen. He has more than 25 years of experience in boundary layer meteorology and is now for more than 10 years deeply involved in atmospheric and oceanic measurements with respect to offshore wind energy deployments. He is also director of the national Norwegian infrastructure OBLO (Offshore Boundary Layer Observatory), that provides access to state-of-the-art instrumentation for met-ocean measurements relevant for offshore wind energy resarch.
Derek has been in the Wind Engineering industry for more than 23 years. In his undergraduate program at the University of Western Ontario, Derek had the opportunity to be taught by notable professors such as, Allan Davenport, Nick Isyumov and Barry Vickery. In 1998 he joined RWDI as a Technical Coordinator, working as a project engineering, overseeing wind tunnel tests and performing the wind engineering analysis on high-rise towers, stadiums and long-span bridges. During this period Derek also completed his master’s degree which he did part-time at McMaster University in Hamilton, Ontario. The subject of his thesis was comparing full scale turbulence properties at the Cooper River Bridge project site, to those modelled in the wind tunnel. In 2005 Derek became a Project Manager, leading projects and working more closely with clients. Throughout this period Derek has worked on some of the tallest buildings in North America and China.
Derek has been a General Manager at RWDI and now sits on RWDI’s Board of Directors.