Improvement of wind turbine aerodynamic performance by vanquishing stall with active multi air jet blowing

The effects of jet blowing on blade suction side of NREL phase VI horizontal axis wind turbine (HAWT) for alleviation of degraded flow due to boundary layer separation were investigated. A 3D innovative multi jet blade is simulated using FLUENT 18.2 software applying SST k -u turbulence model. The spanwise blade portions for jets are outer, middle and inner. Furthermore, twelve jets with 0.04 local chord width have deployed in four chordwise locations of x/c = 0.1, x/c = 0.3, x/c = 0.5 and x/c = 0.7. The torque is sensitive to some dimensionless parameters such as Tip Speed Ratio (TSR) and jet velocity ratio (VR). At the best condition, torque increases about two times with respect to baseline blade. The jet velocity ratios are 1.2, 2.0, 2.4, 2.8, and 3.2. Applying changes in jet parameters, the flow pattern and quality improved. Also, the aerodynamic torque synergy of combinations of two, three and four jets were compared with that of a single jet and the direct relationship between the number of activated jets and the increase in torque was proved. The results showed that jets in blade outer part, have more effects in aerodynamic performance of rotor than the other blade portions. T1 jet produced the highest increase in torque. ? 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study investigated the effects of jet blowing on the blade suction side of a horizontal axis wind turbine, aiming to alleviate flow degradation caused by boundary layer separation. It was found that under optimal conditions, torque increased by about two times compared to baseline blades, and changes in jet parameters improved flow patterns and quality. The outer jets on the blade had a greater impact on the aerodynamic performance of the rotor, with T1 jet producing the highest torque increase.