Table 1 Wells turbine modification using passive flow control.

Single suction slot²²

Torque coefficient increased by 40%, operating range by 17%

Multiple suction slots²³

Torque coefficient increased by 26.7%, operating range by 51%

Undulating leading edge²⁴

Operating range increased by 12.5%

Gurney flap²⁵

The torque coefficient increased by 10.7%

Static extended trailing edge²⁶

Power output increased by 97%, Operating range increased by 22%

Endplate²⁷

Peak efficiency increased by 16%

Stall fence (SF)²⁸

The operating range increased by 16.7%