Numerical simulation of synthetic, buoyancy-induced columnar vortices

Much of the solar energy incident on the Earth’s surface is absorbed into the ground, which in turn heats the air layer above the surface. This buoyant air layer contains considerable gravitational potential energy. The energy in this layer can drive the formation of columnar vortices (“Dust Devils”) which arise naturally in the atmosphere. A new energy harvesting approach makes use of this phenomena by creating and anchoring the vortices artificially and extracting energy from them. In this document, we explore the characteristics of these vortices through numerical simulation. Computational models of the turning vane system which generates the vortex and the turbine used to extract energy have been developed and are presented here. These models have been tested against available experimental measurements and high fidelity simulations. Results from these studies are investigated, as well as details of the columnar vortex structure. Finally, we introduce a new approach used to optimize the system configuration to maximize the power extraction and the resulting proposed configuration from this effort. This work explored a wide variety of configurations and ultimately provides an assessment of the technological feasibility of the overall endeavor.