Rozhkova L. The new shapes of blade profiles of vertical-axial wind turbines of medium speed.

The dissertation proves the possibility and expediency of creation of a new class of vertical-axial wind turbines (WT) of medium speed that work with speed factor 1...3. Till now, this range was almost never used. It is shown that traditional wing blades cannot be efficient in medium-speed WT due to features of air dynamics of a wind wheel. A conception of development of blades for these WT is introduced and new shapes of blade profiles are suggested. A large volume of experimental researches was fulfilled. As a result, flow patterns and factors Cy and Cx were obtained for WU blades (of wing-like unclosed profile) under circular blowing with various angles of inflow. Besides, power characteristic curves of rotors with WU blades and two-element blades were obtained. As it was found out, the most efficient profiles for medium-speed WT are those updated WU-6 and two-element bi-profile. These blades provide self-start of the rotor and achievement of high efficiency in using the wind power, both at small and large velocity of wind. A technique for computation of geometrical parameters of wind wheel and operational characteristics of WT on the basis of obtained model power characteristics of WT with the developed blades is suggested. The criteria for selection of way of fastening of blades using the results of the performed researches are determined.The performed work contains practically important results for further development of wind engineering.