DATE: Wednesday, September 23, 2020
TIME: 12:00 – 1:00pm
ROOM: ZOOM Meeting #
Topic: Global Environmental Multiscale and Urban Microclimate Modeling of Extreme Events and their impacts on buildings
Speaker: Dr. Liangzhu (Leon) Wang, Associate Professor, Center for Zero Energy Building Studies, Concordia University
The recent heatwaves, droughts, and forest fires across the world, such as Australia, Canada, and the US, have shown undoubted proof of climate change. As a result, the intensity, duration, and frequency of these extreme weather events have risen dramatically. Meanwhile, urbanizations are picking up the pace with mounting needs of energy from urban agglomerations. The combination of climate change, urbanization, and limited energy resources has created unprecedented challenges. The conventional approach focusing on a single length or time scale is becoming inadequate to address the challenges spanning from the global environment to the local building scale and from the short-term forecast weather to the long-term future climate. This seminar covers our recent work on multi-scale downscaling simulations from macroclimate, meso-climate and to microclimate and building scales by integrating the Global Environmental Multiscale (GEM) developed by the Environment and Climate Change Canada, our in-house models, City Fast Fluid Dynamics (CityFFD) for urban microclimate and City Building Energy Model (CityBEM) for urban building thermal and energy modeling. CityFFD is a Large Eddy Simulation (LES) model running on graphics processing units (GPU) with high-order semi-Lagrangian interpolation algorithms for both time and space. The model can simulate whole city aerodynamics and thermal conditions within a few hours on a single GPU. CityBEM is a physics-based simulation model for urban thermal loads and energy uses. The model takes as the inputs, including building information: geometry, construction materials, lighting, HVAC, and building uses and operations: occupancy schedules, lighting, plug-loads, and thermostat settings, so it is possible to run the annual calculations on an hourly or shorter-time-step basis. From macroclimate/meso-climate to microclimate, CityFFD exchanges data with the GEM (i.e., GEM-SURF: surface prediction system), and then automatic data exchange is achieved between CityFFD and CityBEM to integrate the urban microclimate with building simulations. We showed our validation studies at different scales for these models and demonstrated the multi-scale downscaling modeling for the study of a historical snowstorm and recent heatwaves. Some on-going work on short-term forecasting simulations and long-term climate impact modeling will also be reported, including some recent work on COVID-19 risks and the impacts.
Bio: Dr. Liangzhu (Leon) Wang is currently an associate professor, the Centre for Zero Energy Building Studies (CZEBS) at Concordia University, Montreal, Canada. He joined Concordia in August 2010. He earned a Ph.D. degree in Mechanical Engineering from Purdue University in 2007 and then worked as a postdoctoral research associate at the Building and Fire Research Laboratory (BFRL) of the National Institute of Standards and Technology (NIST) at Gaithersburg, Maryland, USA. Dr. Wang is a voting member of the TC 4.10 - Indoor Environmental Modeling of ASHRAE, and the editorial member of Energy and Buildings. Dr. Wang received the Best Paper Award from Building and Environment, and the BFRL Distinguished Associate Award of the US NIST. His current research focuses on urban microclimate and building thermal and energy modeling, building scaling and similarity, zero energy building technologies, and building fire safety.