Effect of solidity on aerodynamic forces around straight-bladed vertical axis wind turbine by wind tunnel experiments (depending on number of blades)

The evaluation of tangential coefficient, normal coefficient, lift coefficient, drag coefficient, power and torque performance at four different solidities were investigated. In order to verify the aerodynamic forces characteristics of the straight-bladed VAWT, pressure distribution on the surface of the rotor blades were measured by multiport pressure devices during rotation in wind tunnel experiments. Moreover, the fluctuations of the power coefficient were compared by the six-component balance, pressure distribution and torque meter, respectively.251