Passive Flow Control Methods for Performance Augmentation in Air Turbines Used for Wave Energy Conversion—A Review

The performance enhancement of air turbines used in wave energy extraction is quintessential to realize the commercialization of wave energy plants. This chapter discusses the various passive flow control methods used to enhance the performance of the Wells and axial impulse air turbines that are employed in the oscillating water column to harvest energy. The different passive flow control methods were elaborated with their effect on the performance parameters of the air turbines, and it was found that the implemented passive flow control devices addressed critical limitations such as narrow operating range, reduced efficiency, and low power output, etc. Moreover, the combined investigation of different passive flow control devices was suggested to achieve the overall performance enhancement of the Wells turbines. Lastly, only a handful of literature is available on the passive flow control of the axial impulse turbines, and dedicated research was recommended to analyze and implement compatible passive flow control devices to improve their performance.