Civil-Transport Wing Design Concept Exploiting New Technologies

Abstract

Current trends in the design of transport aircraft have shown that in order to be economically viable and competitive it is necessary to investigate technologies which may give an improvement in performance and operational flexibility goal, but must be shown to be cost-effective. The current competitive environment forces the airlines to buy advanced technology aircraft and requires manufacturers to provide more operational flexibility, without drastic performance penalties. This is a challenging task, which might be solved by the use of new technologies. It is believed that the application of a Hybrid Laminar Flow Control (HLFC) and Variable Camber (VC) to a wing would assist in achieving such a task. This paper describes an investigation aimed to examine the suitability of an aerodynamic wing design, allowing for the use of a combined HLFC-VC concept for transonic transport aircraft. The paper describes the phenomenon of laminar flow and outlines the wing design process. It then discusses the benefits and penalties of the variablecamber wing concept. Description is then given of the aerodynamic design of a wing which incorporated both laminar flow and variable camber technologies. It concludes with a discussion of the results and recommendations for future work.

Numerical Study of Variable Camber Continuous Trailing Edge Flap at Off-Design Conditions

“…The initial studies of VCCTEF have been conducted by deploying it on the airframe of the GTM wing. Edi et al [16] reviewed the new technologies related to the wing design of civil-transport aircraft and had considered the combination of HLFC-VCW on the wing of advanced technology regional aircraft (ATRA) [19]. The present work reports the combination of HLFC-VCCTEF on ATRA wing's outboard airfoil.…”

“…There can be a loss of laminar flow if there is a variation in lift coefficient and Mach number due to the change in the designed pressure distribution. A combination of HLFC and Variable Camber Wing (VCW) techniques suggested that the variable camber (flap deflection at a low angle of attack) can maintain the designed pressure distribution at off-design conditions, to obtain an optimum benefit [16].…”

Supercritical natural laminar flow airfoil optimization for regional aircraft wing design

“…In order to maintain laminar flow, and to improve optimization efficiency, the quantity of the FPG, denoted as Q FPG = −dC p /dX, are applied in the optimization. On the front part of airfoil, where X < 0.50, for both upper and lower surfaces Q FPG should be larger than 0.0. dC p /dX is limited to be less than 3.0 on the pressure recovery region ( X > 0.70) to avoid trailing edge separation [8]. …”

“…Laminar flow length could be achieved through maintaining Favorable Pressure Gradient (FPG, or negative pressure gradient) [8]. However, the FPG should not be so great as to avoid excessive shock strength [8]. Nevertheless, the quantitative influence of FPG on drag of supercritical NLF airfoil is not so clear.…”

“…The design problem becomes how to achieve laminar length and how to reduce shockwave drag. Laminar flow length could be achieved through maintaining Favorable Pressure Gradient (FPG, or negative pressure gradient) [8]. However, the FPG should not be so great as to avoid excessive shock strength [8].…”