Rotating cylinder for circulation control on an airfoil

Tennant, J. S.; Johnson, W. S.; Krothapalli, A.

doi:10.2514/3.48147

Cited by 43 publications

(12 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A general introduction to CC can be found in, e.g., [1]. While several different types of CC devices have been proposed in the past (for example, those using a rotating cylinder attached to a truncated trailing edge of a wing [2]), the present paper focuses only on those using Coanda wall jet blowing over a rounded trailing edge.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of Wind-Tunnel Sidewall Effects on Circulation Control Airfoil Flows

Nishino

Shariff

2010

AIAA Journal

View full text Add to dashboard Cite

Two-and three-dimensional numerical simulations are performed of the flow around a circulation control airfoil (using a Coanda jet blowing over a rounded trailing edge) placed in a rectangular wind-tunnel test section. The airfoil model spans the entire tunnel and the span-to-chord ratio of the model is 3.26. The objective of this numerical study, in which we solve the compressible Reynolds-averaged Navier-Stokes equations in a time-resolved manner (but the solutions eventually converge to steady states), is to investigate the physical mechanisms of wind-tunnel sidewall effects on the flow, especially in the midspan region. The three-dimensional simulations predict that the Coanda jet flow is quasi-two-dimensional until the flow separates from the trailing edge of the airfoil; however, the spanwise ends of this Coanda jet sheet then three-dimensionally roll up on the side walls of the wind tunnel to form two large streamwise vortices downstream. Careful comparisons between the two-and three-dimensional simulations reveal that the wind-tunnel stream goes below the airfoil more in the three-dimensional cases than in the two-dimensional cases due to the presence of these two streamwise vortices downstream. This results in smaller lift and larger drag being produced at the midspan of the airfoil in the three-dimensional cases than in the two-dimensional cases.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical Study of Wind-Tunnel Sidewall Effects on Circulation Control Airfoil Flows

Nishino

Shariff

2010

AIAA Journal

View full text Add to dashboard Cite

show abstract

“…When the ratio α of the rotational speed to translational speed is moderately high, a Kármán vortex street, Görtler-type vortices and Taylor vortices are generated at the same time. 1 When the ratio is greater than a certain limiting value α L , it is observed that the Kármán vortex street disappears. 2 However, from the early works, it is found that the value of α L is dependent on the Reynolds numbers.…”

Section: Introductionmentioning

confidence: 98%

Numerical Simulation of Flows Past a Rotational Circular Cylinder by Taylor-Series-Expansion and Least Squares-Based Lattice Boltzmann Method

Chen

Niu

et al. 2005

Int. J. Mod. Phys. C

View full text Add to dashboard Cite

An explicit Taylor series expansion and least square-based lattice Boltzmann method (TLLBM) is used to simulate the two-dimensional unsteady viscous incompressible flows. TLLBM is based on the well-known Taylor series expansion and the least square optimization. It has no limitation on mesh structure and lattice model. Its marching in time is accurate. Therefore, it is very suitable for simulation of time dependent problems. Numerical experiments are performed for simulation of flows past a rotational circular cylinder. Good agreement is achieved between the present results and available data in the literature.

show abstract

“…see [7]) and boundary layer control on aerofoils (e.g. see [25]). In wing theory, a flow passing a Joukowski airfoil with an angle of attack and the circulation can be transformed to the flow passing a rotating cylinder in the transformed plane.…”

Section: Introductionmentioning

confidence: 99%

Flow around a rotating cylinder near a plane boundary

Liang

Liou

1995

Journal of the Chinese Institute of Engineers

View full text Add to dashboard Cite

Penalty finite-element solutions have been obtained for steady uniform flow from the left to the right over a clockwise rotating circular cylinder near a plane wall. Results are presented for Reynolds numbers 20 and 40, the non-dimensional speed of rotation of the cylinder 0.0 ~ 0.5 and the gap between the plane wall and the cylinder surface 0.2 ~ 4.5 times the diameter of the cylinder. The motion is assumed to be two-dimensional and to be governed by the Navier-Stokes equations for incompressible fluids. The finite element approach is utilized and the frontal method is used to solve the stiffness matrix. In the cases of the cylinder without rotation, the results show that when the gap is large (H>2D), the effect of the wall makes the pressure on the cylinder surface decrease, and Cl, Cd and Ct increase. When the gap becomes small (H < 2D), it makes the pressure and Cl increase, and Ct and Cd decrease. For the gap H < 0.7D, a recirculation zone is formed on the plane wall behind the cylinder. The smaller the gap, the recirculation zone is closer to the cylinder. The average rate of variation of Cl and Cd for H < 1D is about ten times those for H > 1D.In the cases of the cylinder with rotation, effect of the rotation makes the upper separation point shift upstream and the lower one downstream, the pressure on the lower surface of the cylinder increase and on the upper surface decrease, and Cl increase linearly and Cd decrease non-linearly. But when H > 2D, Cd is independent of the rotation speed of the cylinder. When the rotation speed of the cylinder becomes large enough, the fully reversed flow in the gap occurs; the lower separation point and the wake pair behind the cylinder disappear. The effects of the wall and cylindrical rotation on Cl and Ct may be superposed linearly for H > 1D.In addition, the cylindrical rotation affects mainly the location of the separation point but not the value of the vorticity. It does not alter the central position of the recirculation zone but diminishes its size. When Re = 20, Cl, Cd and Ct vary greatly with H < 1D, but when Re = 40, they

show abstract

Rotating cylinder for circulation control on an airfoil

Cited by 43 publications

References 7 publications

Numerical Study of Wind-Tunnel Sidewall Effects on Circulation Control Airfoil Flows

Numerical Study of Wind-Tunnel Sidewall Effects on Circulation Control Airfoil Flows

Numerical Simulation of Flows Past a Rotational Circular Cylinder by Taylor-Series-Expansion and Least Squares-Based Lattice Boltzmann Method

Flow around a rotating cylinder near a plane boundary

Contact Info

Product

Resources

About