Description
Climate change, the depletion of fossil fuels, population growth, and increased energy costs have resulted in government initiated mandates to increase the influence of green and renewable technologies for energy production. Wind energy is a well-established and abundant renewable resource which is economically competitive with other forms of green energy. Horizontal axis wind turbines (HAWTs) currently dominate the wind energy field due to their high inherent conversion efficiencies but require specific flow criterion to operate efficiently. When flow conditions do not favor the HAWT, the vertical axis wind turbine (VAWT) presents an alternative with advantageous design aspects. Utilizing a HAWT design and benefits from each turbine type, this thesis proposes and investigates two patent pending wind turbines which integrate a HAWT and VAWT onto a single platform to increase energy conversion. The integrated horizontal-vertical axis wind turbine (IHVAWT) combines the horizontal and vertical rotors with a gearing system to increase energy conversion and promote a self-starting turbine. The combined horizontal-vertical axis wind turbine (CHVAWT) maintained separate conversion systems where the turbine could have increased energy conversion across a large range of wind speeds. Bench models of the IHVAWT and CHVAWT were assembled, tested, and compared to standalone HAWTs and VAWTs using a low-speed wind tunnel and measurement equipment. The IHVAWT recorded low efficiencies due to blade design differences and an inadequate gear ratio but provided self-starting and increased energy conversion over the standalone VAWT. The CHVAWT converted comparable or greater energy than the standalone HAWT and VAWT across multiple wind speeds. The acquired results indicated further research is necessary to investigate the IHVAWT gear ratio for blades designed for similar wind speeds.
