The Application of Air-Jet Vortex Generators to Suppress Flow Separation on Helicopter Aerofoil Sections Under Quasi-Steady and Unsteady Conditions

Singh, Chrisminder; Peake, D. J.; Kokkalis, A.; Coton, F. N.; Khadogolian, Vahik

doi:10.2514/6.2004-45

Cited by 3 publications

(2 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Singh et al (85) used pulsed AJVGs to control the flow separations on helicopter blades, demonstrating that pulsed jets could provide the same enhanced performance as steady AJVGs, with significantly reduced mass flow requirements. c) Mass-less jets Stanewsky (5) reviewed wind-tunnel studies of the application of mass-less jets to control the flow over a slotted flap, over which the flow was wholly or almost wholly separated.…”

Section: B) Ajvgsmentioning

confidence: 99%

A review of recent developments in flow control

2005

View full text Add to dashboard Cite

This paper reviews and highlights recent developments of certain aspects of flow control concerned with reducing the drag of, and delaying flow separation on, wings and bodies over which the flow is turbulent. The study is restricted to devices that extend beyond the viscous sub-layer but are on a smaller scale than geometric features of the aircraft (e.g. wing chord).The review is mainly concerned with developments within the UK, although significant developments in other countries are discussed.The review discusses types of flow that need to be controlled, basic features of flow control devices and applications. It concludes with recommendations for future research.

show abstract

Section: B) Ajvgsmentioning

confidence: 99%

A review of recent developments in flow control

2005

View full text Add to dashboard Cite

show abstract

“…The current flow control methods of the suppression of the dynamic stall of the rotor include both passive and active control methods. Passive control methods include vortex generators [10][11][12], Gurney flaps [13][14][15], fixed leading-edge slats [16,17], and fixed-droop leading edges [18]. However, these methods only have a good control effect on the suppression of the dynamic stall of the rotor under the design conditions; when the actual conditions deviate from the design conditions, the control effect is poor.…”

Section: Introductionmentioning

confidence: 99%

Study on Dynamic Stall Control of Rotor Airfoil Based on Coflow Jet

Liu

Chen

Qiu

et al. 2020

International Journal of Aerospace Engineering

View full text Add to dashboard Cite

In this study, a dynamic stall control strategy, called the co-flow jet (CFJ), is applied to the rotor airfoil. The effect of the CFJ on the unsteady dynamic stall characteristics of the rotor airfoil is numerically investigated via numerical simulations of the unsteady Reynolds-averaged Navier-Stokes (URANS) equations coupled with the Spalart-Allmaras (S-A) turbulence model. The numerical methods are validated by a NACA0012 pitching airfoil case and a NACA6415 airfoil case based on the CFJ, and good agreement with experiments is found. Via the study of the typical conditions of CFJ control to suppress the dynamic stall of the OA212 rotor airfoil, it is verified that this method has a good effect on dynamic stall suppression. The diffusion and blending of the turbulent shear layer between the CFJ injection jet and the main flow excite the main flow and enhance its ability to resist the reverse pressure gradient; this suppresses the generation and development of the separation vortex, thereby enhancing the aerodynamic characteristics, improving the hysteresis effect, and increasing the system stability. On this basis, the control parameters of the CFJ are further studied, including the influences of the jet momentum coefficient and the positions and sizes of the injection and suction slots on suppressing the dynamic stall of the rotor airfoil. It is found that there is a jet momentum coefficient that optimizes the suppression effect of the dynamic stall of the rotor airfoil. Moreover, the position of the injection slot is found to have a greater effect on the dynamic stall suppression, while the size of the injection slot and the position and size of the suction slot have little effect.

show abstract

The Effect of Steady and Pulsed Air Jet Vortex Generator Blowing on an Airfoil Section Model Undergoing Sinusoidal Pitching

Prince¹,

Green²,

Coton³

et al. 2019

j am helicopter soc

Self Cite

View full text Add to dashboard Cite

Experimental results are reported on the assessment of steady and pulsed air jet vortex generators (AJVGs) for the suppression of dynamic stall on a sinusoidal pitching RAE9645 airfoil model. Tests at Rec of 1 million, at reduced pitching frequencies between 0.01 and 0.10 were performed with and without steady and pulsed AJVG blowing. The effect of jet momentum coefficient (0.0003< Cμ< 0.0046), jet duty cycle (0.25< DC< 1) and jet pulsing frequency (0.29< F+< 2.93) were investigated. Pulsed air jet blowing with F+ in the range 0.5–1.0 and with a duty cycle in the range 0.4–0.5, was found to be the most effective to achieve full suppression of dynamic stall vortex formation.

show abstract

The Application of Air-Jet Vortex Generators to Suppress Flow Separation on Helicopter Aerofoil Sections Under Quasi-Steady and Unsteady Conditions

Cited by 3 publications

References 9 publications

A review of recent developments in flow control

A review of recent developments in flow control

Study on Dynamic Stall Control of Rotor Airfoil Based on Coflow Jet

The Effect of Steady and Pulsed Air Jet Vortex Generator Blowing on an Airfoil Section Model Undergoing Sinusoidal Pitching

Contact Info

Product

Resources

About