Professor, Building, Civil, and Environmental Engineering
View Theodore (Ted) Stathopoulos's CV
Hatem Alrawashdeh, (Ph.D. student)
Experimental and computational evaluation of wind loads on rooftop solar panels
Solar panels are lightweight structures and wind pressures on their surfaces may be critical and may affect their structural integrity. Current wind codes and standards of practice provide emerging design provisions for common configurations of solar panels. Despite the amount of research that has been conducted to enrich the knowledge in wind-induced loads on solar panels, research in this area is still lacking and producing contradictory results. There are still many obstacles to the appropriate wind tunnel testing of these elements - scaling factors and blockage ratios are typical examples. Indeed, in order to fulfill the delicate scaling and instrumentation requirements for solar panel models in atmospheric boundary layer wind tunnels, larger models may be desirable. However, this condition may lead to unreliable wind simulations. Therefore, it is necessary to establish specific guidelines for wind tunnel testing of solar panels to be considered in subsequent experimentation to avoid the present ambiguities across previous studies’ results. Geometric test scaling is considered a key parameter in the simulation and has not yet been investigated adequately. It is then proposed that several wind tunnel experiments will be conducted at different scales (1:200, 1:100,1:50, etc.) in parallel with computational approaches based on CFD techniques. Then, comprehensive parametric experiments will be conducted to yield credible results for codification purposes and guidelines to be used by manufacturers and designers.
Murad Aldoum, (Ph.D. student)
Wind loads on rectangular and irregular buildings
Cladding and secondary component wind pressure coefficients provided by the Canadian code for buildings with rectangular plans basically emanate from studies conducted 40-50 years ago. These coefficients have remained almost unchanged until this time. However, as the wind pressure measurement tools have significantly improved during the past 50 years, verification should be made for wind provisions of rectangular buildings using experimental data obtained by modern pressure measurement devices. It is planned to test several rectangular buildings with different roof slopes and shapes in the wind tunnel, including a nearly flat roof, 45°-gabled roof, and stepped roof buildings. Buildings with irregular (i.e., nonrectangular) plans such as L-shaped and T-shaped buildings have not received adequate attention from wind tunnel investigators. Therefore, wind loads on irregular buildings are described shortly and shyly, if at all, in the current building codes and standards. Numerous tests will be performed at the wind tunnel to create a dataset for irregular buildings which will be used to evaluate the design wind loads. In addition, the dataset will be used as a training set for a machine learning model to predict wind loads for irregular buildings.
Theodore Potsis, (Ph.D. student)
Tuning the virtual wind tunnel for design of low-rise buildings
The use of computational fluid dynamics in wind engineering has rapidly expanded in the last decades in both scientific research and practical applications. Turbulence features in the lower atmospheric boundary layer, that interact with low-rise structures, consist of a very challenging modelling topic; especially for peak loads that are needed for design. Current state-of-the-art tools for estimating fluctuating wind loads on building envelopes are out of the computational reach of practitioners and introduce many complexities. To address that, a tuning procedure is researched between the virtual and the physical wind tunnel, based on simple assumptions and minimum computational burden. Wind tunnel experiments are used to extract velocity time-series, which are adapted to fit certain parameters. The adapted time series are then introduced in the computational domain, where the values of interest are calculated. Results regarding the turbulence statistics, spectral content and peak pressure coefficients on building envelopes correlate well with experiments. The importance of inlet conditions in computational procedures is highlighted and the adequate accuracy is discussed, as to create a uniform computational procedure for design of low-rise buildings against wind loads that can be easily applied by modern practitioners.
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