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The sweeping jet is proved to have a lift augmentation efficiency that is not at all inferior to that of the The indicator to quantitatively compare the lift augmentation efficiencies of the CCWs driven by different jetĪctuators. Then, a new index, namely, the energy coefficient-based lift augmentation ratio, is proposed as Higher lift generation performance, verifying that the unsteady lateral oscillation of the sweeping jet is also critical to Besides, compared to the discrete steady jets with the same jet spacing, the sweeping jets boast a notably Indicates that the sweeping jets reduce the air consumption by virtue of higher jet velocities at the expense of higher The accordingly plotted curves of the liftĬoefficient versus the energy coefficient for continuous steady jets and sweeping jets almost overlap each other, which Namely, the energy coefficient, is used to quantify the energy expenditure. Therefore, in the light of this contradiction, a more comprehensive indicator, The other hand, with respect to the mass flow coefficient, the sweeping jet can reduce the air consumption by 48%Ĭompared to the continuous steady jet. Of the velocity ratio and the momentumcoefficient, the continuous steady jet is the most efficient to enhance the lift.On Four dimensionless parameters characterizing the jetīlowing intensity are used to comprehensively evaluate the lift augmentation capacity of the three types of jet. Method and compared with continuous and discrete steady jets. In view of the high air consumption for the conventional steady jet toĭrive the circulation control wing (CCW), the emerging sweeping jet is proposed herein as an alternative excitation This control methodology highlights that in order to improve the aerodynamic performances, novel fluidic actuators providing access to the orientation of the jets could enable breakthroughs for high-Reynolds-number experimental demonstrators.Ĭirculation control (CC) is an airfoil lift augmentation technique that replaces mechanical structures by means ofĪerodynamic flaps generated by high-speed jets. This study suggests that in order to improve the control authority, the LGPC strategy is sufficiently mature. In the case of leading-edge separation conditions, LGPC builds a control law performing similarly to the best open-loop strategy while minimizing the actuation power. In particular, the lift-to-drag ratio is improved by 4% compared to the best open-loop strategy, which corresponds to a relative increase by a factor 3. Results are reported for Reynolds numbers at both half a million and one million. For angles of attack at the onset of stall, we show that the best control law is able to outperform the best open-loop control strategy in the case of a single-input multiple-output control loop. Pressure sensors are located along the chord, at mid-span, and are used in a feedback control strategy where the symbolic control laws are optimized using a linear genetic programming control (LGPC) algorithm. The objective of the control is to improve the lift-to-drag ratio using an array of variable velocity jets located at the leading edge of the wing model. Machine learning control is applied in real-time to an airfoil equipped with variable-velocity jets and pressure sensors in a closed-loop wind tunnel.