Effect of Gurney Flaps on an Elliptical Airfoil

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Lance W. Traub
Keyword(s):  
Reynolds Number ◽  
Wind Tunnel ◽  
Separated Flow ◽  
Pitching Moment ◽  
Airfoil Surface ◽  
Low Speed ◽  
Gurney Flaps ◽  
Lift Curve ◽  
The Impact ◽  
Low Speed Wind Tunnel

A low-speed wind tunnel investigation is presented characterizing the impact of Gurney flaps on an elliptical airfoil. The chordwise attachment location and height of the flaps were varied, as was the Reynolds number. The results showed strong nonlinearities in the lift curve which were present for all tested geometries. Flap effectiveness was seen to diminish as the flap was moved closer to the trailing edge stemming from flap submersion in separated flow. For the tested cases, the measured lift coefficients showed a weak Re dependency. The upper airfoil surface was shown to carry approximately 80% of the total lift load. The top surface caused a pitching moment reversal associated with nonlinearity in the lift curve.

Particle drift potential of glyphosate plus 2,4-D choline pre-mixture formulation in a low-speed wind tunnel

2020 ◽  
Vol 34 (4) ◽  
pp. 520-527
Author(s):  
Bruno C. Vieira ◽  
Thomas R. Butts ◽  
Andre O. Rodrigues ◽  
Jerome J. Schleier ◽  
Bradley K. Fritz ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Droplet Size ◽  
Droplet Velocity ◽  
Target Movement ◽  
Spray Droplet ◽  
Low Speed ◽  
Particle Drift ◽  
Drift Potential ◽  
The Impact ◽  
Low Speed Wind Tunnel

AbstractThe introduction of 2,4-D–resistant soybean and cotton provided growers a new POST active ingredient to include in weed management programs. The technology raises concerns regarding potential 2,4-D off-target movement to sensitive vegetation, and spray droplet size is the primary management factor focused on to reduce spray particle drift. The objective of this study was to investigate the droplet size distribution, droplet velocity, and particle drift potential of glyphosate plus 2,4-D choline pre-mixture (Enlist Duo®) applications with two commonly used venturi nozzles in a low-speed wind tunnel. Applications with the TDXL11004 nozzle had larger DV0.1 (291 µm), DV0.5 (544 µm), and DV0.9 (825 µm) values compared with the AIXR11004 nozzle (250, 464, and 709 µm, respectively), and slower average droplet velocity (8.1 m s−1) compared with the AIXR11004 nozzle (9.1 m s−1). Nozzle type had no influence on drift deposition (P = 0.65), drift coverage (P = 0.84), and soybean biomass reduction (P = 0.76). Although the TDXL11004 nozzle had larger spray droplet size, the slower spray droplet velocity could have influenced the nozzle particle drift potential. As a result, both TDXL11004 and AIXR11004 nozzles had similar spray drift potential. Further studies are necessary to understand the impact of droplet velocity on drift potential at field scale and test how different tank solutions, sprayer configurations, and environmental conditions could influence the droplet size and velocity dynamics and consequent drift potential in pesticide applications.

Cellular Vortex Shedding From Linearly Tapered Finite Cylinders

2020 ◽  
Author(s):  
David M. Rooney ◽  
John C. Vaccaro ◽  
Rafael Smijtink
Keyword(s):  
Reynolds Number ◽  
Wind Tunnel ◽  
Aspect Ratio ◽  
Finite Length ◽  
Vortex Shedding ◽  
Circular Cylinders ◽  
Hot Wire ◽  
Low Speed ◽  
Low Speed Wind Tunnel ◽  
Number Of Cells

Abstract Hot-wire measurements were taken in the wake of ten finite length circular cylinders, six of which were also tapered, in a uniform flow in a low speed wind tunnel. The Reynolds number based on mean cylinder diameter ranged from 2100 ≤ Re ≤ 5500, the aspect ratio (AR) of the cylinders varied from 16 ≤ AR ≤ 64, and the taper ratio (RT) varied from 21.3 ≤ RT ≤ 96. The vortex shedding along the spans of the cylinders coalesced into discrete cells, the range of Strouhal numbers and the number of cells being a function of the cylinder aspect ratio and taper ratio. It was found that the number of discrete cells is linearly related to a cylinder geometry ratio (CGR) defined as CGR = AR(1 + AR/RT).

scholarly journals Solar Panel Effect on Low-Speed Airfoil Aerodynamic Performance

2020 ◽  
Author(s):  
Mostafa El-Salamony ◽  
Mohamed Aziz
Keyword(s):  
Reynolds Number ◽  
Pressure Distribution ◽  
Parametric Study ◽  
Low Reynolds Number ◽  
Aerodynamic Performance ◽  
Solar Panel ◽  
Airfoil Surface ◽  
Low Speed ◽  
Panel Size ◽  
The Impact

Abstract Although the solar panel is thin, its thickness is considerable compared to the airfoil thickness. This paper aims to evaluate the impact of adding the solar panel over an airfoil of a UAV of type AG 34, which is low camber airfoil suitable for low-Reynolds number flights. Three configurations are examined to stand on the most suitable configuration. The analysis is based on the airfoil characteristics (lift, drag, and moment) and the pressure distribution over the airfoil surface. A parametric study is conducted to study the effect of the solar panel size and position on the aerodynamic performance.

Design and Construction of a Low Speed Wind Tunnel

2016 ◽  
Author(s):  
Odenir de Almeida ◽  
FREDERICO CARNEVALLI DE MIRANDA ◽  
Olivio Neto ◽  
Fernanda Guimarães Saad
Keyword(s):  
Wind Tunnel ◽  
Low Speed ◽  
Low Speed Wind Tunnel ◽  
Design And Construction

scholarly journals Numerical analysis of high-lift configurations with oscillating flaps

2021 ◽  
Author(s):  
Johannes Ruhland ◽  
Christian Breitsamter
Keyword(s):  
Reynolds Number ◽  
Flow Separation ◽  
Separated Flow ◽  
Navier Stokes ◽  
Rotational Axis ◽  
High Lift ◽  
Hinge Point ◽  
Reduced Frequency ◽  
Flap Deflection ◽  
The Impact

AbstractThis study presents two-dimensional aerodynamic investigations of various high-lift configuration settings concerning the deflection angles of droop nose, spoiler and flap in the context of enhancing the high-lift performance by dynamic flap movement. The investigations highlight the impact of a periodically oscillating trailing edge flap on lift, drag and flow separation of the high-lift configuration by numerical simulations. The computations are conducted with regard to the variation of the parameters reduced frequency and the position of the rotational axis. The numerical flow simulations are conducted on a block-structured grid using Reynolds Averaged Navier Stokes simulations employing the shear stress transport $$k-\omega $$ k - ω turbulence model. The feature Dynamic Mesh Motion implements the motion of the oscillating flap. Regarding low-speed wind tunnel testing for a Reynolds number of $$0.5 \times 10^{6}$$ 0.5 × 10 6 the flap movement around a dropped hinge point, which is located outside the flap, offers benefits with regard to additional lift and delayed flow separation at the flap compared to a flap movement around a hinge point, which is located at 15 % of the flap chord length. Flow separation can be suppressed beyond the maximum static flap deflection angle. By means of an oscillating flap around the dropped hinge point, it is possible to reattach a separated flow at the flap and to keep it attached further on. For a Reynolds number of $$20 \times 10^6$$ 20 × 10 6 , reflecting full scale flight conditions, additional lift is generated for both rotational axis positions.

scholarly journals The Low Speed Wind Tunnel of Kawasaki Heavy Industries, Ltd.

1983 ◽  
Vol 1983 (17) ◽  
pp. 41-50
Author(s):  
Kazushi OGAWA ◽  
Yoshinori SAKAI ◽  
Kazutoshi MATSUDA
Keyword(s):  
Wind Tunnel ◽  
Low Speed ◽  
Low Speed Wind Tunnel
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