Proposal of spiral ladder blade vertical axis wind turbine with self-starting ability

In order to improve the self-starting characteristics of the lift type vertical axis wind turbine, this paper proposes to replace the traditional straight blade with spiral ladder blade. When the turbine is in a state of static or low TSR, The blade whose leading edge is windward will form a stable detached vortex with larger lift and smaller drag, while the blade whose trailing edge is windward will form a slagnant area with smaller lift and larger drag (namely, stall); Since those two blades are centrosymmetric, the turbine will be affected by a net torque. When the turbine is at the state of high TSR, both of the leading edges will be windward and the wind turbine will enter the attached eddy flow pattern with high efficiency.