Grant: Research Tools and Instruments

In nature, a tornado is described as a rapidly rotating column of air associated with a localized thunderstorm. However, measuring and predicting tornadoes on a real scale can be challenging, and it commonly relies on using mobile Doppler radars combined with physical observation techniques. In contrast, hurricanes are larger and more predictable tropical storms that form over warm ocean waters. The interesting "Fujiwhara Effect" is a meteorological phenomenon that occurs when two nearby hurricanes interact with each other-the upshot of this interaction involves the two hurricanes rotating (or dancing) around a common center, merging with or repelling one another depending on their size, intensity, and relative distance. Although it is difficult to study the interaction of multiple tornadoes or hurricanes in real-life situations, it is possible to generate a controllable tornado-like vortex (TLV) on a laboratory scale to investigate tornado-building interactions-this is of great interest for mechanical and civil engineering applications. However, most studies concerning TLV dynamics have focused only on a single vortex. Research on the interaction of multiple vortices and the associated vortex instability (merging/breakup) and flow control is rare. Consequently, the research to be conducted in the current proposal is seminal. This proposal aims to fabricate a novel small-scale experimental apparatus consisting of modular units capable of generating up to four tornadoes with different strengths, orientations, and distances between them. Furthermore, complementary Computational Fluid Dynamics (CFD) simulations will be conducted to provide the concentration fields of a water vapor tracer to better quantify the efficiency of the ventilation system. Finally, an intelligent control algorithm based on the Adaptive-Network-based Fuzzy Inference System methodology will be developed on Graphics Processing Units (GPUs) with training datasets obtained from our CFD calculations using large-eddy simulation and supplemented with experimental flow visualization. Four high-speed cameras will post-process the images captured by an open-source image processing software to generate velocity fields and streaklines to validate our CFD solutions. The Field Programmable Gate Array-based CompactRIO controllers and actuators [hood blowers, direct current (DC) fans, and stepper motors] will be integrated into the apparatus to maximize the energy efficiency of a ventilation system or remove contaminant aerosols/vapors in an indoor environment under different operating conditions. The long-term goal of this research is to develop a smart ENERGY STAR ventilation system based on multiple controllable TLVs to meet the requirements for high-efficiency products in Canada. (ENERGY STAR is a symbol used to identify the best energy performers on the market as promoted by Natural Resources Canada.)