Pulsed Coand\u{a} Effect for Wind Energy Generation.

The pulsed Coand\u{a} effect was used alternately on the sides of a spring-stabilized circular cylinder to extract energy from the wind in the form of reciprocating motion. This radically new wind-energy generation concept is ideally suited to high-pressure positive displacement pumping used for reverse-osmosis desalination, because it eliminates electrical generator and motor inefficiencies. Flow visualization experiments were performed to identify the time-scales associated with dynamic flow attachment and separation. Subsequently, a proof-of-concept scale-model technology demonstrator was constructed, which consisted of a vertically-mounted, spring-stabilized Coand\u{a} circular cylinder that was equipped with two span-wise blowing slots. It was connected, via a sting, to a one-degree-of-freedom pivot at its lower end and loaded with a positive displacement pump. Measurements included the static loads generated by the Coand\u{a} effect and system power performance evaluations. The former were used, together with a dynamical system model, for performance predictions. Direct system performance measurements demonstrated a positive net power output, while model predictions indicated efficiencies of approximately 20{\%}. System efficiency can be greatly improved by using two blowing slots on either side of the cylinder or by allowing two-degree-of-freedom oscillations.