Wind Tunnel Investigation of a Flexible Wing High-Lift Configuration with a Variable Camber Continuous Trailing Edge Flap Design

Abstract

This paper presents wind tunnel experimental results of a flexible wing high-lift configuration with a variable camber continuous trailing edge flap (VCCTEF) design for drag minimization, tested at the University of Washington Aeronautical Laboratory (UWAL) in July of 2014. The objective of the high-lift test in UWAL is to assess the high-lift performance of the VCCTEF. The wing bending stiffness is tailored to achieve a wing tip deflection of about 10% of the wing semi-span at 1-g flight conditions. The VCCTEF is a multi-segment flap design having three chordwise camber segments and five spanwise flap sections for a total of 15 individual flap elements. The high-lift design includes a Variable Camber Krueger (VCK) leading edge device and an inboard high-lift trailing edge flap with a Fowler motion. Two inboard high-lift flap configurations are tested: a single-element plain flap and a three-segment cambered flap. The outboard VCCTEF is rigged at varying flap deflections of up to 30 • formed by a circular arc camber and has no Fowler motion. A premature flow separation associated with the initial configuration of the VCK leading edge device, as indicated by an abrupt stall, was encountered during the initial runs. A final VCK configuration was found experimentally with a varying rigging angle from 65 • at the inboard to 50 • at the outboard. Wind tunnel test results indicate a C L max = 2.13 is achieved for a wing-body configuration with the single-element plain flap versus C L max = 2.09 with the cambered flap. This C L max is close to the desired C L max for a typical Boeing 757 landing configuration. The cambered flap achieves a L/D improvement by 6% over the single-element plain flap due to the reduced profile drag with the cambered flap. Sensitivities due to VCCTEF spanwise deflection shapes, combined Reynolds number / aeroelastic effect, and Fowler slot width were studied. Reynolds / aeroelastic and Mach number corrections

Progress on Gust Load Alleviation Wind Tunnel Experiment and Aeroservoelastic Model Validation for a Flexible Wing with Variable Camber Continuous Trailing Edge Flap System

“…The second wind tunnel test was conducted in 2014 to assess the high-lift performance of the VCCTEF. 13,14 The high-lift wind tunnel model incorporates one variable camber Fowler flap at the inboard as part of the VCCTEF system along with a variable camber Krueger continuous leading edge slat. The test results show that the VCCTEF can achieve the necessary high-lift C L max requirement.…”

Havacilik Ve Uzay Uygulamalarinda Şeki̇l Hafizali Alaşimlar

“…Şekil 9. NASA ve Boeing işbirliği ile yapılan esnek kanat kenar tasarımları [32] Bu yöndeki çalışmalar, NASA Armstrong Uçuş Araştırma Merkezi tarafından FlexFoil adıyla 2014 yılında gerçek uçuşlarda test edilmeye başlanmış ve başarılı sonuçlar alınmıştır (Şekil 10). Testler sırasında esnek kanat teknolojisi, Gulfstream III jeti üzerinde denenmiştir.…”

Numerical study on technical and conceptual improvements to a civil aircraft trailing-edge flap using passive/active flow control

“…However, the multi-hinges increase the structural weight and mechanism complexity. This concept can adaptively change the camber to improve the cruise economy, but its performance as a high-lift device is poor, and the disclosed design also retains the inboard Fowler flap to ensure sufficient lift (Nguyen et al, 2015). These simplified flaps have apparent benefits for the weight and cruise drag, but the lift loss requires additional weight and power requirements of the AFC system (Hartwich et al, 2014;Melton et al, 2019;Vatsa et al, 2018).…”