Aerodynamics of Delta Wings with Application to High- Alpha Flight Mechanics

McCormick, Barnes W.

doi:10.1007/978-3-642-45720-3_23

Cited by 55 publications

(81 citation statements)

References 10 publications

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“…Eckalbar [9] gives the wetted surface area as estimated by Stinton [10] as 620 ft 2 for the V-35 and estimates that the wetted surface area of the conventional-tailed model E33A as 620 ft 2 . Using McCormick's [8] value for the skinfriction coefficient and Eckalbar's [9] estimate for the wetted surface area yields an equivalent parasite drag area of 3:14 ft 2 , which agrees quite well with the current flight-test result for f 0 of 3:125 ft 2 . A literature search revealed no similar flight-test data for partialspan partially deflected flaps.…”

Section: Resultssupporting

confidence: 76%

Flight Determination of Partial-Span-Flap Parasite Drag With Flap Deflection

Rogers

2010

Journal of Aircraft

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Level-flight performance tests were conducted on a typical light general aviation single-engine retractable aircraft with partially and fully extended partial-span single-slotted flaps in both gear-up and gear-extended configurations. A parabolic variation in the aircraft equivalent parasite drag area with flap deflection was observed for both configurations. A linear relation was discovered between the aircraft equivalent parasite drag area and the square of the flap deflection angle for both configurations. This result suggests that level-flight performance tests in the stowed and fully extended flap configurations will yield adequate data for estimating performance for intermediate flap deflections. A similar linear relation was confirmed for an NACA 23012 airfoil equipped with a single-slotted flat using classical NACA wind-tunnel data. The flight tests showed that the aircraft equivalent parasite drag area increased by a factor of 1.16 at 10, by 1.81 at 20 , and by 3.14 at a full flap deflection of 32 in the gear-up configuration. With the gear extended, the equivalent parasite drag area increased by a factor of 1.14 at 10 , by 1.29 at 20, and by 1.67 at the 32 full flap deflection. The results are expected to be typical for similar aircraft.= two-dimensional section lift coefficient c = airfoil or wing chord e = Oswald efficiency factor f = aircraft equivalent parasite drag area R 2 = square of the correlation coefficient S = wing reference area THP req = thrust horsepower required THP req std = thrust horsepower required at standard weight and altitude V = true airspeed V std = true airspeed at standard weight and altitude W = weight of the aircraft f = flap deflection angle = density SL = density at sea level = ratio of the density at altitude to that at sea level, = SL

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Section: Resultssupporting

confidence: 76%

Flight Determination of Partial-Span-Flap Parasite Drag With Flap Deflection

Rogers

2010

Journal of Aircraft

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“…The coefficient of lift variation is compared with the theoretical lift coefficient variation given by McCormick's formula (McCormick [17]). According to McCormick's formula, the lift curve slope depends on the aspect ratio by…”

Section: Force-based Experimental Resultsmentioning

confidence: 99%

On the Wake Properties of Segmented Trailing Edge Extensions

Gunasekaran

Curry

2018

Aerospace

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Changes in the amount and the distribution of mean and turbulent quantities in the free shear layer wake of a 2D National Advisory Committee for Aeronautics (NACA) 0012 airfoil and an AR 4 NACA 0012 wing with passive segmented rigid trailing edge (TE) extensions were investigated at the University of Dayton Low Speed Wind Tunnel (UD-LSWT). The TE extensions were intentionally placed at zero degrees with respect to the chord line to study the effects of segmented extensions without changing the effective angle of attack. Force based experiments were used to determine the total lift coefficient variation of the wing with seven segmented trailing edge extensions distributed across the span. The segmented trailing edge extensions had a negligible effect on the lift coefficient, but showed a measurable decrement in the sectional and total drag coefficient. Investigation of turbulent quantities (obtained through Particle Image Velocimetry (PIV)) such as Reynolds stress, streamwise and transverse root-mean square (RMS) in the wake, reveal a significant decrease in magnitude when compared to the baseline. The decrease in the magnitude of turbulent parameters was supported by the changes in coherent structures obtained through two-point correlations. Apart from the reduction in drag, the lower turbulent wake generated by the extensions has implications in reducing structural vibrations and acoustic tones.

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“…One lift equation is the one derived by Dudley and Ellington (subscript DE), Equation (2), and the second equation is derived by Weis-Fogh (subscript W-F), shown in Equations (3) and (4). In this section, these dimensionless numbers, η L , C L DE , and C L W´F are calculated for three bumblebees during hovering flight.…”

Section: Evaluation Of C L and η L Of Hovering Bumblebeesmentioning

confidence: 99%

“…The absence of the average angular velocity impedes the direct application of Equation (1) to evaluate the lift-generating capability of flapping wings. In order to apply the equation to flapping wings, the average angular velocity ω must be inserted in Equation (1) by means of an artificial computational construct, the blade element method (BEM) [4] (p. 347), which result in Equations (2) and (3). This construct consists in dividing the flapping wing into a large number of chordwise elements along its span R. Each of these elements of infinitesimally small width are immersed in a unique local flow field that vary along the length of the flapping wing and must be defined a priori by adding the translation velocity vector v 8 (accounted for in Equation (1)) to the local average tangential velocity v tg due to average angular velocity ω of the flapping wing (both velocities v tg and ω are not accounted for in Equation (1)).…”

Section: Introductionmentioning

confidence: 99%

Comparison of the Average Lift Coefficient ͞CL and Normalized Lift ͞ηL for Evaluating Hovering and Forward Flapping Flight

Burgers

2016

Aerospace

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Abstract:The capability of flapping wings to generate lift is currently evaluated by using the lift coefficient C L , a dimensionless number that is derived from the basal equation that calculates the steady-state lift coefficient C L for fixed wings. In contrast to its simple and direct application to fixed wings, the equation for C L requires prior knowledge of the flow field along the wing span, which results in two integrations: along the wing span and over time. This paper proposes an alternate average normalized lift η L that is easy to apply to hovering and forward flapping flight, does not require prior knowledge of the flow field, does not resort to calculus for its solution, and its lineage is close to the basal equation for steady state C L . Furthermore, the average normalized lift η L converges to the legacy C L as the flapping frequency is reduced to zero (gliding flight). Its ease of use is illustrated by applying the average normalized lift η L to the hovering and translating flapping flight of bumblebees. This application of the normalized lift is compared to the same application using two widely-accepted legacy average lift coefficients: the first C L as defined by Dudley and Ellington, and the second lift coefficient by Weis-Fogh. Furthermore, it is shown that the average normalized lift η L has a physical meaning: that of the ratio of work exerted by the flapping wings onto the surrounding flow field and the kinetic energy available at the aerodynamic surfaces during the generation of lift. The working equation for the average normalized lift η L is derived and is presented as a function of Strouhal number, St.

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Aerodynamics of Delta Wings with Application to High- Alpha Flight Mechanics

Cited by 55 publications

References 10 publications

Flight Determination of Partial-Span-Flap Parasite Drag With Flap Deflection

Flight Determination of Partial-Span-Flap Parasite Drag With Flap Deflection

On the Wake Properties of Segmented Trailing Edge Extensions

Comparison of the Average Lift Coefficient ͞CL and Normalized Lift ͞ηL for Evaluating Hovering and Forward Flapping Flight

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