Wind-tunnel investigation of a fighter model at high angles of attack

1992 ◽  
Vol 29 (6) ◽  
pp. 1091-1097 ◽  
Author(s):  
Sheshagiri K. Hebbar ◽  
David H. Leedy
Keyword(s):  
Wind Tunnel ◽  
High Angles Of Attack

scholarly journals Validation of Control Laws at High Angles of Attack Using Three-Degree-of-Freedom Dynamic Rig in Wind Tunnel

2019 ◽  
Vol 52 (12) ◽  
pp. 526-531
Author(s):  
Maria E. Sidoryuk ◽  
Alexander N. Khrabrov ◽  
Timur G. Mukhanov ◽  
Igor I. Grishin
Keyword(s):  
Wind Tunnel ◽  
Degree Of Freedom ◽  
Control Laws ◽  
Three Degree Of Freedom ◽  
High Angles Of Attack

scholarly journals Experimental and Computational Investigation of Spoiler Deployment on Wing Stall

2021 ◽  
Author(s):  
Scott Lindsay
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Computational Study ◽  
Lift Coefficient ◽  
Wind Tunnel Experiment ◽  
Chord Length ◽  
Aerodynamic Efficiency ◽  
Stall Angle ◽  
Wing Stall ◽  
High Angles Of Attack

Upper surface flaps commonly referred to as spoilers or drag brakes can increase maximum lift, and improve aerodynamic efficiency at high, near-stall angles of attack. This phenomenon was studied experimentally and computationally using a 0.307626 m chord length NACA 2412 airfoil in six different configurations, and one baseline clean configuration. A wind tunnel model was placed in the Ryerson Low Speed Wind Tunnel (atmospheric, closed-circuit, 3 ft × 3 ft test section) at a Reynold’s number of approximately 780,000 and a Mach number of 0.136. The wind tunnel study increased the lift coefficient by 0.393%-2.497% depending on the spoiler configuration. A spoiler of 10% chord length increased the maximum lift coefficient by 2.497 % when deflected 8º, by 2.110% when deflected 15º, and reduced the maximum lift coefficient by 2.783% when deflected 25º. A spoiler of 15% chord length produced smaller maximum lift coefficient gains; 0.393% when deflected 8º, by 1.760% when deflected 15º, and reduced the maximum lift coefficient by 4.475% when deflected 25º. Deflecting the spoiler increased the stall angle between 37.658% and 87.544% when compared with the clean configuration. The drag coefficient of spoiler configurations was lower than the clean configuration at angles of attack above 18º. The combination of the increased lift and reduced drag at angles of attack above 18º created by the spoiler configurations resulted in a higher aerodynamic efficiency than the clean configuration case. A 10% chord length spoiler deflected at 8º produced the highest aerodynamic efficiency gains. At low angles of attack, the computational study produced consistently higher lift coefficients compared with the wind tunnel experiment. The lift-slope was consistent with the wind tunnel experiment lift-slope. The spoiler airfoil stall behaviour was inconsistent with the results from the wind tunnel experiment. The drag coefficient results were consistent with the wind tunnel experiment at low angles of attack. However, the spoiler equipped airfoils did not reduce drag at high angles of attack. Therefore, the computational model was not valid for the spoiler configurations at high angles of attack.

scholarly journals Design and implementation of an unmanned aerial vehicle with self-propulsive wing

2019 ◽  
Vol 11 (6) ◽  
pp. 168781401985729 ◽  
Author(s):  
Abdelrahman Kasem ◽  
Ahmad Gamal ◽  
Amr Hany ◽  
Hesham Gaballa ◽  
Karim Ahmed ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Rotational Speed ◽  
Lift Coefficient ◽  
Cross Flow ◽  
Unmanned Air Vehicle ◽  
Air Vehicle ◽  
Cross Flow Fan ◽  
High Angles Of Attack

The article aims to prove the effectiveness of the proposed unmanned air vehicle design (The Propulsive Wing) through numerical and experimental means. The propulsive wing unmanned air vehicle is a completely new class of unmanned air vehicle, making disruptive changes in the aircraft industry. It is based on a distributed cross-flow electric fan propulsion system. When the fan starts to operate, the flow is drawn from the suction surface, provided by energy through the fan and expelled out of the airfoil trailing edge (TE). This causes a significant lift increase and drag reduction with respect to ordinary aircrafts, making it perfect for applications requiring low cruise speed such as firefighting, agriculture, and aerial photography. In this early stage of the investigation, our main aim is to prove that this design is applicable and the expected aerodynamic and propulsion improvements are achievable. This is done through a two-dimensional computational fluid dynamics investigation of the flow around an airfoil with an embedded cross-flow fan near its TE. A scaled wind tunnel model of the same geometry used in the computational fluid dynamics investigation was manufactured and used to perform wind tunnel testing. The computational fluid dynamics and wind tunnel results are compared for validation. Furthermore, an unmanned air vehicle model was designed and manufactured to prove that the propulsive wing concept is flyable. The article shows that the aerodynamic forces developed on the cross-flow fan airfoil are not only functions of Reynolds number and angle of attack as for standard airfoils but also function of the fan rotational speed. The results show the great effect of the rotational speed of fan on lift augmentation and thrust generation through the high momentum flow getting out of the fan nozzle. Wind tunnel tests show that the suction effect of the fan provides stall free operation up to very high angles of attack (40 degrees) leading to unprecedented values of lift coefficient up to 5.8. The flight test conducted showed the great potential of the new aircraft to perform the expected low cruise speed and high angles of attack flight.

PLASMA FLOW CONTROL OVER FOREBODY AT HIGH ANGLES OF ATTACK

2010 ◽  
Vol 24 (13) ◽  
pp. 1405-1408 ◽  
Author(s):  
ZIJIE ZHAO ◽  
CHAO GAO ◽  
FENG LIU ◽  
SHIJUN LUO
Keyword(s):  
Wind Tunnel ◽  
Flow Control ◽  
Plasma Flow ◽  
Vortex Pair ◽  
Apex Angle ◽  
Plasma Actuators ◽  
Pressure Measurements ◽  
Asymmetric Vortex ◽  
Plasma Flow Control ◽  
High Angles Of Attack

Forward blowing from a pair of plasma actuators on the leeward surface and near the apex is used to switch the asymmetric vortex pair over a cone of semi-apex angle 10° at high angles of attack. Wind tunnel pressure measurements show that by appropriate design of the actuators and appropriate choice of the AC voltage and frequency, side forces and yawing moments of opposite signs can be obtained at a given angle of attack by activating one of the plasma actuators. Further work is suggested.

LOW SPEED WIND TUNNEL TEST OF THE JET TRAINER MODEL AT HIGH ANGLES OF ATTACK

2016 ◽  
Vol 23 (4) ◽  
pp. 471-478
Author(s):  
Kamil Smędra ◽  
Rafał Świerkot ◽  
Krzysztof Kubryński
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Low Speed ◽  
Low Speed Wind Tunnel ◽  
High Angles Of Attack
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