Flow Structure on Nonslender Delta Wing: Reynolds Number Dependence and Flow Control

Zharfa, Mohammadreza
Ozturk, Ilhan
Yavuz, Mehmet Metin
The flow structure over a 35 deg swept delta wing is characterized in a low-speed wind tunnel using techniques of laser-illuminated smoke visualization, laser Doppler anemometry, and surface-pressure measurements. The effects of Reynolds numbers and attack angles on the evaluation of flow patterns are addressed within the broad range of Reynolds number 10(4) < Re < 10(5) and attack angle 3 deg < alpha < 10 deg. In addition, the effect of steady blowing through the leading edges of the wing on flow structure is studied to delay three-dimensional surface separation. A comparison of two different blowing patterns, uniform blowing and decreasing blowing, is used to identify the effective regions on leading edges considering the ultimate influence of flow control. The results indicate that the effect of Reynolds number on flow structure is limited, such that beyond a certain Reynolds number, the flow structure demonstrates minimal variations with further increase in Reynolds number. Considering the results of the flow-control study, steady blowing through leading edge significantly alters the flow structure, and is quite effective in the eradication of three-dimensional surface separation. The decreasing-blowing pattern compared to uniform blowing seems to be more efficient on the overall flow structure, indicating that control through leading edge near the apex region is more effective.


Experimental analysis of flow structure on moderate sweep delta wing
Öztürk, İlhan; Yavuz, Mehmet Metin; Department of Mechanical Engineering (2014)
Experimental investigation of flow over a 45° moderate swept delta wing is performed using laser illuminated smoke visualization, surface pressure measurements, and Laser Doppler Anemometry (LDA) techniques in low-speed wind tunnel. The formation of leading-edge vortices and their breakdown, and three-dimensional separation from the surface of the wing are studied at broad range of attack angles and Reynolds numbers. Smoke visualizations are performed at three different cross flow planes along with vortex a...
Control of Flow Structure over a Nonslender Delta Wing Using Periodic Blowing
Cetin, Cenk; Celik, Alper; Yavuz, Mehmet Metin (2018-01-01)
The effect of unsteady blowing through the leading edge on the flow structure over a 45 deg swept delta wing in relation to the steady blowing is experimentally studied in a low-speed wind tunnel using the techniques of surface-pressure measurements, particle image velocimetry, and laser-illuminated smoke visualization. The unsteady blowing in the form of a periodic square pattern at 25% duty cycle is provided at the excitation frequencies varying from 2 to 24 Hz for a fixed momentum coefficient. The flow s...
Effect of Passive Bleeding on Flow Structure over a Nonslender Delta Wing
Celik, Alper; Cetin, Cenk; Yavuz, Mehmet Metin (2017-08-01)
The effect of passive bleeding on flow structure of a 45 deg swept delta wing is studied in a low-speed wind tunnel using techniques of laser-illuminated smoke visualization, surface-pressure measurements, and particle image velocimetry. Three different bleeding configurations are tested to identify the effectiveness of the control technique compared to a base planform for a broad range of attack angles 6 <= alpha <= 6deg at Reynolds numbers Re=3.5x10(4) and Re=10(5). The results indicate that all bleeding ...
Numerical and experimantal analysis of flapping motion
Sarıgöl, Ebru; Alemdaroğlu, Hüseyin Nafiz; Department of Aerospace Engineering (2007)
The aerodynamics of two-dimensional and three-dimensional flapping motion in hover is analyzed in incompressible, laminar flow at low Reynolds number regime. The aim of this study is to understand the physics and the underlying mechanisms of the flapping motion using both numerical tools (Direct Numerical Simulation) and experimental tools (Particle Image Velocimetry PIV technique). Numerical analyses cover both two-dimensional and three-dimensional configurations for different parameters using two differen...
Control of flow structure on delta wing with steady trailing-edge blowing
Yavuz, Mehmet Metin (2006-03-01)
The near-surface flow structure and topology are characterized of a delta wing of low sweep angle, which is subjected to trailing-edge blowing. A technique or high-image-density particle image velocimetry is employed to determine the topological critical points adjacent to the surface and in the near wake of the wing, in relation to the dimensionless magnitude of the blowing coefficient. These topological features are, in turn, interpreted in conjunction with patterns of surface-normal vorticity and near-su...
Citation Formats
M. Zharfa, I. Ozturk, and M. M. Yavuz, “Flow Structure on Nonslender Delta Wing: Reynolds Number Dependence and Flow Control,” AIAA JOURNAL, pp. 880–897, 2016, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40788.