Control of Separation on the Flap of a Three-Element High-Lift Configuration

Günther, Bert; Thiele, Frank; Petz, Ralf; Nitsche, W.; Sahner, J.; Weinkauf, Tino; Hege, Hans-Christian

doi:10.2514/6.2007-265

Cited by 26 publications

(11 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the present work, the URANS calculations are performed using the multi-purpose parallel CFD code ELAN [7,8]. ELAN is an incompressible finite volume solver based on the SIMPLE algorithm.…”

Section: Numerical Solversmentioning

confidence: 99%

“…The additional longitudinal momentum due to actuation delays or even completely suppresses the flow separation. Various researchers have performed several experimental [2,3,4,5,6] and numerical investigations [7,8,9] to study the effect of actuation in delaying the separation on the flap and enhancing the overall aerodynamic performance of high-lift configurations. In the present work, synthetic jets, also known as zero-netmass-flux actuators [10,11] are employed to control the flow separation on the suction side of the flap.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Two-Level Hybrid Approach for Optimal Active Flow Control on a Three-Element Airfoil

Nemili¹,

Özkaya²,

Gauger³

et al. 2016

Proceedings of the VII European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS Congress 2016)

Self Cite

View full text Add to dashboard Cite

Abstract. In this paper we present a two-level approach that combines an adjoint-based gradient search method with an evolutionary algorithm for optimal active flow control. The suggested method effectively combines the advantages of both approaches and achieves a good compromise between the computational effort and the degree of freedom used in optimization. In the first level, a global optimization is performed with few design parameters using an evolutionary algorithm. In the second level, the global optimal solution from the first level is taken as the initial setting for the adjoint based local optimization using a large number of design parameters. The unsteady discrete adjoint solver required for the second level is developed based on Algorithmic Differentiation techniques for the unsteady incompressible flowsgoverned by Unsteady Reynolds-Averaged Navier Stokes (URANS) equations. In this way, the discrete adjoint solver is robust and has exactly the same functionality with the underlying URANS flow solver. The applicability of the two-level method is demonstrated by finding the optimal parameters of the active flow control mechanism on a three element airfoil configuration at a Reynolds number of Re = 10 6 and an angle of attack of AoA = 6 • . Numerical results have shown that the hybrid approach completely suppressed the separation and very significantly increased the mean-lift coefficient by 67% compared to the un-actuated baseline flow.

show abstract

Section: Numerical Solversmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Two-Level Hybrid Approach for Optimal Active Flow Control on a Three-Element Airfoil

Nemili¹,

Özkaya²,

Gauger³

et al. 2016

Proceedings of the VII European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS Congress 2016)

Self Cite

View full text Add to dashboard Cite

show abstract

“…It can be concluded that employing typical high-lift systems for different kinds of aircrafts can fulfill that requirements. But like it is stated by Gunther, et al [2] instead of complex multi-element high-lift devices for improvement of lift aerodynamics of ultra-light aircraft wing, a single slotted flap is desirable.…”

Section: mentioning

confidence: 99%

“…Gunther, et al [2] quotes, "The wings of commercial aircrafts must generate a tremendous amount of lift during take-off and landing in order to reduce ground speeds and runway lengths". It can be concluded that employing typical high-lift systems for different kinds of aircrafts can fulfill that requirements.…”

Section: mentioning

confidence: 99%

Study the Influence of a Gap between the Wing and Slotted Flap over the Aerodynamic Characteristics of Ultra-Light Aircraft Wing Airfoil

Velkova¹,

Todorov²,

Durand³

2015

JMEA

View full text Add to dashboard Cite

Abstract:The purpose of the study is to assess what the influence of the distance of the gap is between the wing and slotted flap on the aerodynamic characteristics of ultra-light aircraft wing when the flap is retracted. It has been elected numerical approach to the study and it is been realized through applied numerical model of the wing airfoil NACA 2412 for three different lengths of slotted gap size, whose length is expressed as percentages of the airfoil chord. The code ANSYS FLUENT has been applied, as it has been determined RANS (Reynolds-averaged Navier-Stokes) equations and DES (detached-eddy simulation) turbulent model has been used.

show abstract

“…Rumsey et al performed a study on synthetic jet flows entering into a turbulent boundary layer through a circular orifice [12]. W. Nitsche et al studied flap separation control by introducing periodic excitation near a flap for high-lift configuration [13,14]. Kim and Kim numerically investigated the frequency-dependent flow control mechanism of synthetic jets on an airfoil, and proposed multi-location synthetic jets to mitigate the unstable flow structure of a high-frequency jet [15].…”

Section: Introductionmentioning

confidence: 99%

Experimental and Computational Study on Separation Control Performance of Synthetic Jets with Circular Exit

Kim¹,

Lee²,

Jun-Hee³

et al. 2016

International Journal of Aeronautical and Space Sciences

View full text Add to dashboard Cite

This paper presents experimental and computational investigations of synthetic jets with a circular exit for improving flow control performance. First, the flow feature and vortex structure of a multiple serial circular exit were numerically analyzed from the view point of flow control effect under a cross flow condition. In order to improve separation control performance, experimental and numerical studies were conducted according to several key parameters, such as hole diameter, hole gap, the number of hole, jet array, and phase difference. Experiments were carried out in a quiescent condition and a forced separated flow condition using piezoelectrically driven synthetic jets. Jet characteristics were compared by measuring velocity profiles and pressure distributions. The interaction of synthetic jets with a freestream was examined by analyzing vortical structure characteristics. For separation control performance, separated flow over an airfoil at high angles of attack was employed and the flow control performance of the proposed synthetic jet was verified by measuring aerodynamic coefficient. The circular exit with a suitable hole parameter provides stable and persistent jet vortices that do beneficially affect separation control. This demonstrates the flow control performance of circular exit array could be remarkably improved by applying a set of suitable hole parameters.

show abstract

Control of Separation on the Flap of a Three-Element High-Lift Configuration

Cited by 26 publications

References 17 publications

A Two-Level Hybrid Approach for Optimal Active Flow Control on a Three-Element Airfoil

A Two-Level Hybrid Approach for Optimal Active Flow Control on a Three-Element Airfoil

Study the Influence of a Gap between the Wing and Slotted Flap over the Aerodynamic Characteristics of Ultra-Light Aircraft Wing Airfoil

Experimental and Computational Study on Separation Control Performance of Synthetic Jets with Circular Exit

Contact Info

Product

Resources

About