Winglet Geometry Impact on DLR-F4 Aerodynamics and an Analysis of a Hyperbolic Winglet Concept

Abstract

Abstract:In this article, the growth of aerodynamic efficiency and the growth of the wing structural stress is studied for DLR-F4 typical transport aircraft wing-body, after installing classical Whitcomb winglets of different configurations and a delta wingtip fence. A new-concept curved-span winglet was mathematically developed and approved through Computational Fluid Dynamics (CFD) and static structural experiments, revealing the interaction of sub-and transonic air flow dynamics with the wingtip device geometry. The design space of the winglet geometry was explored briefly, and an evaluation of the lift-to-drag ratio increment depending on various winglet input parameters was performed. In particular, the winglet cant angle effect on lift and drag was thoroughly analyzed at various flow regimes and angles of attack, revealing an ambiguity and a conflicting character of results between highly canted winglets and nearly vertical ones. As a result of cant angle impact analysis, a curved winglet concept is suggested and mathematically parametrized, that could provide an innovative solution, alternative to a morphing winglet, but much simpler with a fixed structure. In conclusion, a multidisciplinary winglet efficiency estimation criterion is suggested for comparing the aerodynamic efficiency of different wingtip devices with respect to their structural weight penalty in real flight conditions.

Conceptual Design and Performance Optimization of a Tip Device for a Regional Turboprop Aircraft

“…For a typical passenger aircraft configuration flying at higher subsonic speeds than the Jetstream 31 of the present study, significant aerodynamic and structural benefits have been observed for the cruise condition by using the 'curved winglet concept' suggested by Gueraiche and Popov [45]. Their proposed winglet design is considered a fair compromise between classic, low cant angle Whitcomb winglets and 'lifting' large cant angle winglets.…”

Computational Fluid Dynamics Study of Wing in Air Flow and Air–Solid Flow Using Three Different Meshing Techniques and Comparison with Experimental Results in Wind Tunnel

“…The Mosaic mesh of the present work uses the Poly-Hexcore method and consists of 2,607,133 cells, with a minimum orthogonal quality of 0.196808 and a maximum skewness of 0.803192. Having taken into consideration the inflation used by Gueraiche [16], and following trial and error, 15 inflation layers were used, with the last-ratio method. The first layer height was chosen to be 0.0015 mm, aiming to retain the value of y + < 5.…”

Investigation of a Light Boxplane Model Using Tuft Flow Visualization and CFD

“…Based on numerous validation studies of turbulence modelling and external flow problems-for instance [25][26][27][28]-the shear stress transport (SST) kturbulence model was chosen for this study, providing the best accuracy to computational cost for the studied case. Bardina et al [25] demonstrated the advantages of SST kfor flow separation prediction, both its onset and the size of separated area.…”