A hybrid approach for evaluating wind flow over a complex terrain

Wind speeds over a complex terrain were estimated using a hybrid approach consisting of numerical and large scale wind tunnel simulations. Numerical simulations were performed to identify three critical wind directions out of 12 different wind directions (0 degrees-330 degrees at 30 degrees intervals). These simulations provided the inflow conditions for the wind tunnel tests since the area of topography modeled in the numerical simulation was much larger compared to the wind tunnel test model. Wind tunnel tests were conducted at the state-of-the-art wind testing facility, the Wind Engineering, Energy and Environment (WindEEE) Dome, where the multi-fan (60 fans) inlet facilitated replication of the inflow as determined by the numerical simulations for each of the three critical wind directions. Mean and 3-s gust wind speeds were calculated at 17 different locations on the topography for each of the three critical wind directions. Speed-Up factors at each location were obtained for the most conservative wind speed and then compared with the speed-up factors recommended by the National Building Code of Canada. In general, the building code over-predicted the speed-up factors on the complex topography investigated in the present study.