A typical vertical axis wind turbine (VAWT) consists of two or more airfoils all attached to a single central axis. The wind turbine style most commonly found in renewable energy is the horizontal axis wind turbine (HAWT) that have a high energy production efficiency in exchange for requiring large amounts of land and air space. Alternatively, a VAWT can function in low speeds and in smaller less typical locations. As a result, novel VAWT designs are researched to improve their energy efficiency. An example of a novel VAWT is the concentric counter-rotating VAWT investigated theoretically using the 2D computational fluid dynamic (CFD) software Ansys Fluent. A mesh sensitivity analysis is conducted to optimize resource usage during the simulations. Three mesh sizes were chosen for both geometries and tested at three different rotational velocities. The power generation of the double rotor system was shown to be greater than the single in all cases except for at 600 rpms where the single set produced 2.43 kW and the double rotor produced only 2.12 kW. Further investigation is necessary to improve upon the functioning CFD model to further improve the simulation accuracy. However, the interactions between energized air and shed low pressure vortices show a positive aerodynamic interaction between the two rotors and demonstrate the potential for the concentric counter-rotating VAWT to produce energy more efficiently.
Class: IRES Projecthttps://commons.und.edu/es-showcase/1011/thumbnail.jp
