Geometry and Aerodynamic Performance of Parabolic Trailing-Edge Flaps

Hunsaker, Douglas F.; Reid, Jackson T.; Moorthamers, Bruno; Joo, James J.

doi:10.2514/6.2018-1278

Cited by 13 publications

(8 citation statements)

References 7 publications

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“…The fits resulting from the third stage describe the airfoil aerodynamic coefficients as a function of both angle of attack and flap deflection which makes it more convenient to use with MachUp than looking up separate functions for both variables. Further details of parabolic flap as well as the camber control by flaps and the theory the airfoil database script is based on are found in[27] and[28]. Note that the Reynold's number for the elliptically loaded wing differs from that of the wing with the optimal lift distribution due to the difference in chord lengths discussed in Chapter 2.…”

mentioning

confidence: 99%

Comparison of Induced and Parasitic Drag on Wings with Minimum Induced Drag

Abdel-Motaleb

Taylor

Hunsaker

et al. 2019

AIAA Scitech 2019 Forum

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Minimizing the induced drag for steady level flight is a variational problem that requires solving for the optimum lift distribution given a set of design constraints. From lifting-line theory, minimizing the induced drag is, in part, achieved by varying the Fourier coefficients used to describe the section lift. The elliptic lift distribution minimizes the induced drag for a wing with fixed weight and wingspan by setting all but the first coefficient to zero. If wingspan is allowed to vary, a negative third Fourier coefficient is utilized to reach an optimum lift distribution that further reduces the induced drag for stress-limited designs. However, to produce an optimal section-lift distribution for minimum induced drag, the wing is required to vary twist along the span, which contributes to the parasitic drag component and may compromise the benefits gained from minimizing the induced drag. Here, the effect of these lift distributions on the parasitic drag is investigated. It is shown that twisting the wing to produce optimal lift distribution that minimizes induced drag can increase the parasitic drag values enough to nearly cancel or surpass the benefits gained by the reduction of the induced drag depending on the aircraft and flight conditions. One aircraft example is studied. Other aircraft might have different results.

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mentioning

confidence: 99%

Comparison of Induced and Parasitic Drag on Wings with Minimum Induced Drag

Abdel-Motaleb

Taylor

Hunsaker

et al. 2019

AIAA Scitech 2019 Forum

Self Cite

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show abstract

“…A parabolic flap deflects with the camber line conforming to a curved parabolic shape, rather than the single-joint articulation of a traditional flap. Studies have geometrically defined and examined the aerodynamic performance of a parabolic flap [13]. The geometries for a deflected articulated flap and deflected parabolic flap on a NACA 2412 airfoil are shown in Fig.…”

Section: A Articulated and Conformal Control Surfacesmentioning

confidence: 99%

“…This adverse pressure gradient causes the flow to separate earlier along the surface of the wing compared to a parabolic flap. This causes the parabolic flap to produce less drag with changes in lift [13]. Another benefit to the parabolic flap can be shown in the flap effectiveness.…”

Section: A Articulated and Conformal Control Surfacesmentioning

confidence: 99%

“…Another benefit to the parabolic flap can be shown in the flap effectiveness. The ideal section flap effectiveness can be calculated for articulated and parabolic flaps using thin-airfoil theory [13]. This effectiveness is defined as the change in zero lift angle of attack resultant from a change in flap deflection.…”

Section: A Articulated and Conformal Control Surfacesmentioning

confidence: 99%

“…For further study of the ARCS geometry, the reader can retrieve the code used to create this geometry * . The geometric definition of a parabolic flap [13] may be used to examine the parabolic deflection of any geometry. Examples of the ARCS geometry deflected parabolically are shown in Fig.…”

Section: F Airfoil Recambering Compliant System (Arcs)mentioning

confidence: 99%

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