Numerical Investigations of the Vertical Axis Wind Turbine with Guide Vane

Abstract

More than ever, the generation of energy from renewable sources has become one of the most critical and challenging areas of human activity. This is the result of a number of factors acting simultaneously, including the highly publicized greenhouse effect, the need to reduce CO2 emissions, the dwindling of natural resources and thus the need to protect them, including the preservation of wealth (among other natural resources) for future generations. This paper presents a numerical investigation of the operation of a vertical axis wind turbine with guide vanes. The work analyzes the obtained power on the turbine rotor for different numbers of rotor blades and different numbers of guide vanes, as well as for different proportions of the width of the rotor ring and the guide ring. The analyses carried out point to the potential feasibility of using this type of design in practice. The obtained power coefficient is higher than that of classical vertical axis wind turbines. The analyses also indicate that the proposed design solution can be optimized to increase the efficiency of wind energy extraction.

Investigation of a cross-flow wind turbine with a hybrid frontal guiding device

“…This is achieved by providing a sufficiently large open section after the runner. So far with best performance is the cylindrical guiding apparatus, in which the guide vanes (most often arc-shaped) are evenly placed around the runner [1][2][3]. In front of the passive area of the runner, the guide vanes act as a deflector and repelling the flow that creates a negative torque [4].…”

“…The runner can reach maximum efficiency between 8-12% [16][17][18][19][20] at stream velocities above 4 m/s (two times lower limit, compared to the other VAWTs). Adding a proper guiding device can double the efficiency up to 22% [1][2][3] and decrease the rated speed to 4 m/s. As a result, we can accumulate the same amount of energy under the same conditions with 2.26 times smaller overall dimensions, compared to a bare turbine.…”

Investigation of a cross-flow wind turbine with frontal deflector

“…Many studies have proven that the cross-flow wind turbine is one of the most efficient VAWTs in conditions of slow and variable wind [5][6][7][8]. Its power can be improved with appropriate guiding devices [9][10][11][12]. The authors propose a frontal arc-shaped deflector that reflects the wind from the passive area of the runner, in which the blades are moving against the wind.…”