Active Flow Control Upon Cavities At Low Reynolds Numbers

There has been a recent surge of interest in powered resonance tube actuators for flow control applications. Additional features of powered resonance tube actuators (both experiments and simulations) are presented in this paper. A Powered Resonance Tube (PRT) is a device based on aeroacoustics principles, capable of producing intense perturbation levels for use in active flow control. The PRT described here is capable of producing frequencies ranging from 1600 to 15,000 Hz at amplitudes as high as 160 dB near the source. Our detailed experiments aimed at understanding the PRT phenomenon are complemented by improved direct numerical simulations. We provide a detailed characterization of the unsteady pressures in the nearfield of the actuator using phase averaged pressure measurements. The measurements revealed that propagating fluctuations were biased towards the upstream direction (relative to the supply jet) for some frequencies. However, this feature depended on the frequency at which the device was operated. The simulations that were performed earlier at a Reynolds number 490 times lower than that in the experiment have been refined. The current simulations are performed at 49 times lower than that in the experiments and show that a finer scale structure develops at higher Reynolds numbers and a more regular oscillation is present at low Reynolds numbers.

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Low Reynolds Number Laminar Airfoil with Active Flow Control

5th Flow Control Conference ◽

10.2514/6.2010-4579 ◽

2010 ◽

Cited By ~ 12

Author(s):

Michael Thake ◽

Nathan Packard ◽

Carlos Bonilla ◽

Jeffrey Bons

Keyword(s):

Reynolds Number ◽

Flow Control ◽

Low Reynolds Number ◽

Active Flow Control ◽

Low Reynolds ◽

Active Flow

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Research of the suction flow control on wings at low Reynolds numbers

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410017694057 ◽

2017 ◽

Vol 232 (8) ◽

pp. 1515-1528 ◽

Cited By ~ 5

Author(s):

Dongli Ma ◽

Guanxiong Li ◽

Muqing Yang ◽

Shaoqi Wang

Keyword(s):

Flow Control ◽

Aerodynamic Force ◽

Separation Bubble ◽

Reynolds Numbers ◽

Aerodynamic Characteristics ◽

Flow State ◽

Laminar Separation ◽

Low Reynolds Numbers ◽

Low Reynolds ◽

Suction Flow

Laminar separation and transition have significant effects on aerodynamic characteristics of the wing under the condition of low Reynolds numbers. Using the flow control methods to delay and eliminate laminar separation has great significance. This study uses the method combined with water tunnel test and numerical calculation to research the effects of suction flow control on the flow state and aerodynamic force of the wing at low Reynolds numbers. The effects of suction flow rate and suction location on laminar separation, transition and aerodynamic performance of the wing are further researched. The results of the research show that, the suction can control laminar separation and transition effectively, when the suction holes are in the interior of the separation bubble, and close to the separation point, the suction has the best control effect. When the Reynolds number is Re = 3.0 × 105, the suction flow control can make the lift-to-drag ratio of the wing increase by 8.62%, and the aerodynamic characteristics of the wing are improved effectively.

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