CFD modeling of Vertical Axis Wind Turbine Arrays using Actuator Cylinder Theory

The goal of this thesis is to analyze the flow field and power generation from a vertical axis wind turbine (VAWT) by extending the Actuator Cylinder Model to include the viscous effects. Turbulent flow effects in the Actuator Cylinder Model are modeled by solving the Reynolds-Averaged Navier-Stokes (RANS) equations with the Spalart-Allmaras (SA) turbulence model in ANSYS FLUENT. A study is performed to establish mesh independence of the solutions. Numerical solutions on a fine mesh are compared to existing theoretical results based on inviscid theory for a series of flow conditions and turbine sizes. Similar trends in the present turbulent flow results are found as in the inviscid results for downstream velocity and pressure profiles. The Betz limit is found not to be applicable to vertical axis wind turbines. To consider wake interactions, the Actuator Cylinder Model is extended to two and three turbine cases. Power densities are computed to determine the optimal vertical and downstream distances between turbines. For the application to small scale airborne turbines, an increased freestream velocity is employed with two and three turbine models to simulate the effects on performance and power generation at higher altitudes with greater wind velocity. Differences between the present numerical results and inviscid theory are discussed

CFD Study of Wake Interactions from Multiple Vertical Axis Wind Turbines using Actuator Cylinder Theory

This paper studies the flow field and power generation from Vertical Axis Wind Turbine (VAWT) arrays using an extension of the Actuator Cylinder Model that includes the viscous effects. The ideal spacing for two VAWT arrays is determined by solving the Reynolds-Averaged Navier Stokes (RANS) equations with the Spalart-Allmaras (SA) turbulence model in ANSYS Fluent. Next, a third VAWT is introduced downfield and calculations are repeated to determine the ideal downfield distance for each spacing variation of the leading row of two turbines. Comparisons are made with an isolated vertical axis wind turbine. Differences in generated power are discussed

The Wellness Companion

Issues such as obesity, high blood pressure, and heart disease have been correlated with a sedentary lifestyle. Additionally, many contemporary office jobs consist of deskwork on a computer for almost the entire workday. This can result in back and neck issues. The goal of this project is to limit the harmful effects of sitting for extended periods of time by making an active lifestyle easy and convenient. The Wellness Companion is a portable treadmill that is easy to transport and use in a variety of environments, such as at the library, in school, or at the office