Simplified tunnel correction method

Shindo, Shojiro

doi:10.2514/3.46705

Cited by 34 publications

(9 citation statements)

References 5 publications

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“…The aerodynamic coefficients were corrected using the boundary correction method. 22) Output data from the balance system was acquired at a sampling frequency of 100 Hz, with 500 individual data points for each output.…”

Section: Methodsmentioning

confidence: 99%

Aerodynamic Characteristics of Low-Aspect-Ratio Wings with Various Aspect Ratios in Low Reynolds Number Flows

Mizoguchi

Kajikawa

Itoh

2016

Trans. Japan Soc. Aero. S Sci.

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The effect of the aspect ratio on the stall characteristics of low-aspect-ratio wings is experimentally investigated at a Reynolds number of 5.2©10 4 . The aspect ratio ranges from 0.5 to 1.5 at intervals of 0.1. The aerodynamic coefficients of thin rectangular wings are measured in a low-speed wind tunnel. It is found that the aerodynamic characteristics of lowaspect-ratio wings are significantly sensitive to the aspect ratio. The maximum lift coefficient increases as the aspect ratio decreases toward unity. On the other hand, the difference in lift-to-drag ratio is negligible at large angles. Hysteresis during a stall occurs when the aspect ratio is within a narrow range. The span of the hysteresis loop has its peak at an aspect ratio of 1.0. The discussion also includes the analysis of lift components and flow visualization.

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Section: Methodsmentioning

confidence: 99%

Aerodynamic Characteristics of Low-Aspect-Ratio Wings with Various Aspect Ratios in Low Reynolds Number Flows

Mizoguchi

Kajikawa

Itoh

2016

Trans. Japan Soc. Aero. S Sci.

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“…The closed test section wake-and solidblockage corrections were estimated using a simplified correlation by Shindo [38] for the moderate AR wings (AR > 2). At the highest angle of attack for the largest AR test plate, the corrections for C L and C D were approximately 2.6%.…”

Section: B Aerodynamic Loads Acquisition Systemmentioning

confidence: 99%

Geometry and Prestrain Effects on the Aerodynamic Characteristics of Batten-Reinforced Membrane Wings

Zheng

Martin

Wrist

et al. 2016

Journal of Aircraft

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To lessen the deterioration of fixed-wing aerodynamic performance associated with chord Reynolds numbers below 100,000, flexible membrane wing designs have been studied and proposed as an alternative for micro air vehicle use. The beneficial effects of a flexible membrane can include higher lift, steeper lift-curve slope, delayed stall, gentle stall characteristics, and greater efficiency. These benefits have been attributed to both the time-averaged and dynamic deformation of the membrane. This work discusses the geometric and prestrain effects on a battenreinforced, free trailing-edge membrane wing in low-Reynolds-number (50,000) flow. The global aerodynamic forces on the wings with varying wing aspect ratio, cell aspect ratio, and prestrain level were measured. The results show that the aerodynamic advantages of the flexible membrane are retained for the low-aspect-ratio wings. The optimal membrane cell aspect ratio is found to be approximately 1. The comparison of the aerodynamic forces between the low-aspect-ratio membrane wings and the corresponding three-dimensional-printed wings with the time-averaged deformation indicates the importance of membrane dynamic motion for the derived aerodynamic benefits.

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“…Pitching moments were nondimensionalized using the mean aerodynamic chord c (2c r =3) and taken about a moment reference center at the quarter-chord point (0:5c r ). Solid and wake blockage were corrected for using the method of [24], with downwash corrections from [25]. Balance accuracy was estimated at better than 0.15% in lift, drag, and pitching moment, with pitch angle set to better than 0.1 .…”

Section: Experimental Arrangementmentioning

confidence: 99%

Gurney Flaps on Slender and Nonslender Delta Wings

Greenwell

2010

Journal of Aircraft

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A parametric low-speed wind-tunnel study has been undertaken of the effects of Gurney flap height on the aerodynamic characteristics of delta wings with sweep angles of 40, 60, and 70 . Flap effects on lift and drag are consistent with previous two-dimensional data when wing geometry is accounted for by using the change in zero-lift incidence rather than lift and using the relative flap area rather than flap height. Flap deployment primarily affects the attached-flow potential lift on delta wings, with vortex lift being almost unchanged. Induced-drag factors are considerably reduced as flap height is increased, but this is due to the use of flat-plate models with near-zero leadingedge suction. For control applications, pitch/lift ratios are similar to those for delta wings with conventional trailingedge flaps, but the trim-drag penalties are much higher. An aft shift in loading associated with Gurney flap deployment leads to large aft movements of the aerodynamic center, which significantly reduces control capability.pitching-moment coefficient at zero lift C N = normal force coefficient, N=qS C NP = potential flow component of normal force C NV = vortex lift component of normal force D = drag h = projected flap height (measured from lower surface) K P = potential lift factor, C L K V = vortex lift factor k = induced-drag factor, C D C D min AR=C 2 L L = lift q = dynamic pressure, 1 2 V 2 q = lift increase factor on flap height S = wing area S f = flap frontal area, hb t = wing thickness = angle of attack 0L = zero-lift angle of attack 0P = zero-lift angle of attack for potential lift component 0V = zero-lift angle of attack for vortex lift component = leading-edge sweep angle

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Simplified tunnel correction method

Cited by 34 publications

References 5 publications

Aerodynamic Characteristics of Low-Aspect-Ratio Wings with Various Aspect Ratios in Low Reynolds Number Flows

Aerodynamic Characteristics of Low-Aspect-Ratio Wings with Various Aspect Ratios in Low Reynolds Number Flows

Geometry and Prestrain Effects on the Aerodynamic Characteristics of Batten-Reinforced Membrane Wings

Gurney Flaps on Slender and Nonslender Delta Wings

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