Towards Evaluating the Performance of Vertical Axis Wind Turbine Consist of Slant Straight Blades

In this theoretical study, the effect of variable blade inclination angle or angle of blade slant on power factor Cp of straight blades- vertical axis wind turbine has been studied. Where a slop of angle on the horizontal plane was changed from an angle of 25 degrees to an angle of 85 degrees with the amount of change is equal to 20 degrees. Within the scope of this research, the wind rotor was given the name “straight-slant vertical axis wind turbine” (SS-VAWT). The mathematical model “Multi Stream Tube” was applied in the form of a computer program by using “Microsoft Visual Basic”, with regard to checking the effectiveness of this program, it was done by comparing its theoretical results with previous laboratory results from another researches, as it proved its effectiveness in achieving satisfactory results that fit the aim of this study. This study was conducted on twelve configurations of SS-VAWT, which were divided into four groups which are (H group), (R group), (N group) and (C Group) to study the effect of blade inclination angle at different values of rotor height (H), rotor radius (R), rotor blades number (N) and blade airfoil length (C) respectively and separately. The results are expressed by power curves as a function of tip speed ratio. As the results indicated that angle of blade slant range from 45 degrees to 65 degrees is the best range for rotor blade inclination in terms of obtaining the highest power factor Cp
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in addition to the largest range of tip speed ratio and moreover the angle 45 degree has the advantage of limiting the problem of starting a self-motion.