Optimization of a transonic business jet wing (original) (raw)

Preliminary Aerostructural Optimization of a Large Business Jet

Journal of Aircraft, 2007

An overview of an industrial approach to the aero-structural optimization of a large business jet is presented herein. The optimization methodology is based on the integration of aerodynamic and structural analysis codes that combine computational, analytical, and semi-empirical methods, validated in an aircraft design environment. The aerodynamics sub-space is analyzed with a three-dimensional Transonic Small Disturbance code capable of predicting the drag of a complete, trimmed aircraft within engineering accuracy. The design of the wing structure is accomplished using a quasi-analytical method that defines the layout of the ribs and geometry of the spar webs, spar-caps and skin-stringer panels, and predicts the wing flexural properties and weight distribution. In addition, the prediction of operating economics as well as the integrated en route performance is coupled into the scheme by way of fractional change functional transformations. In order to illustrate the automated design system capabilities, the methodology is applied to the optimization of a large business jet comprising winglets, rear-mounted engines and a T-tail configuration. The aircraft-level design optimization goal in this instance is to minimize a cost function for a fixed range mission assuming a constant Maximum Take-Off Weight.

High-Fidelity Aerostructural Design Optimization of a Supersonic Business Jet

Journal of Aircraft, 2004

This paper focuses on the demonstration of an integrated aerostructural method for the design of aerospace vehicles. Both aerodynamics and structures are represented using high-fidelity models such as the Euler equations for the aerodynamics and a detailed finite element model for the primary structure. The aerodynamic outer-mold line and a structure of fixed topology are parameterized using a large number of design variables. The aerostructural sensitivities of aerodynamic and structural cost functions with respect to both outer-mold line shape and structural variables are computed using an accurate and efficient coupled-adjoint procedure. Kreisselmeier-Steinhauser functions are used to reduce the number of structural constraints in the problem. Results of the aerodynamic shape and structural optimization of a natural laminar-flow supersonic business jet are presented together with an assessment of the accuracy of the sensitivity information obtained using the coupled-adjoint procedure.

Aerodynamic Optimization of Near-future High-wing Aircraft

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2015

This paper discusses aerodynamic optimization of the high-wing configuration to explore fuselage-wing shapes for the high-wing configurations of near-future aircraft, in which it will be possible to install fuel-efficient, ultrahigh-bypass ratio engines, using computational fluid dynamics simulation and the Kriging surrogate-assisted genetic algorithm. First, optimization of the fuselage upper surface is performed, with exploration of the fairing shape suitable for the high-wing configuration. Second, the aircraft nose shape is also optimized, in addition to the fuselage upper surface, to confirm the possibility of generating higher lift by the fuselage itself. Finally, both the fuselage and the wing shape are optimized to improve the lift-to-drag ratio by alleviating the shock wave over the wing, while sustaining the high lift generation of the high-wing configuration. The final optimized configuration achieves not only a lift-to-drag ratio comparable to the DLR-F6, but also a C L approximately 1.5 times higher than the DLR-F6. These results indicate the possibility of producing highwing aircraft that not only employ fuel-efficient ultrahigh-bypass ratio engines, but also have much better aerodynamic performance than low-wing configurations.

Optimisation of a Business Jet

This paper discusses the structural design methodology embedded in a Multidisciplinary Design Optimization (MDO) of a complete aerodynamic representation of a business jet, including winglets, rear-mounted engines, and a T-tail configuration. Particular emphasis is placed on the development of the quasi-analytical structural design methodology, including the layout of the ribs, the design of the spar webs, spar-caps and the skin-stringer panels, and the computation of the wing structural properties and weight. The statement of the MDO problem is reviewed and the MDO methodology is applied to the optimization of an aircraft for a fixed range mission assuming a constant Maximum Take-Off Weight.

Wing Section Optimization for Supersonic Viscous Flow

Journal of Fluids Engineering, 1998

To improve the performance of a highly swept supersonic wing, it is desirable to have an automated design method that also includes a higher fidelity to the flow physics. With this impetus, an aerodynamic optimization methodology incorporating the thin-layer Navier-Stokes equations and sensitivity analysis had previously been developed. Prior to embarking upon the full wing design task, the present investigation concentrated on the identification of effective optimization problem formulations and testing the feasibility of the employed methodology, by defining two-dimensional test cases. Starting with two distinctly different initial airfoils, two independent optimizations resulted in shapes with similar features: cambered, parabolic profiles with sharp leading- and trailing-edges. Secondly, an outboard wing section normal to the subsonic portion of the leading edge, which had a high normal angle-of attack, was considered. The optimization resulted in a shape with twist and camber t...

Wing and Airfoil Optimized Design of Transport Aircraft

An efficient methodology for multi-disciplinary design and optimization of transport was elaborated and developed. The methodology was implemented in a commercial known optimization framework. Semi-empirical methods were employed for wing weight estimation; a multi-block full-potential code was used for drag calculation; Vortex Lattice method was implemented for spanwise lift distribution in order to compute de aircraft maximum-lift coefficient via critical section method; a calibrated singlepoint Breguet simplified equation was considered for aircraft performance calculation. The optimization design variables are related to the wing planform and airfoil geometry and cruise speed. The design constraints were the fuel tank capacity, flight quality of the aircraft, and takeoff field length. A simple stability augmentation control system was implemented in order to compute its effects on optimal configurations. Multi-objective optimization tasks were performed accomplishing minimization of the block time and block fuel for a specified mission.

Combined aerodynamic and structural optimization of a high-speed civil transport wing

36th Structures, Structural Dynamics and Materials Conference, 1995

A combined procedure for the aerodynamic and structural optimization of a High-Speed Civil Transport wing is presented. Primary goal of the procedure is the determination of the jig shape of the wing necessary so that it deforms into its optimum shape in cruise flight. The wing twist and camber distribution is optimized for the cruise condition using WINGDES, a code based on a linearized potential flow solution for zero-thickness lifting surfaces. The structural design is decomposed into three levels. The top level uses the FLOPS aircraft synthesis program to generate preliminary weights, mission, and performance information. The optimization criterion is productivity expressed by a productivity index for the specified mission. The second level of the system performs a finite-element based structural optimization of the wing box with the help of the ASTROS structural optimization tool. The wing structure is sized subject to strength, buckling, and aeroelastic constraints. The buckling constraint information is supplied by the third level where a detailed buckling optimization of individual skin cover panels is performed. The Georgia Tech HSCT baseline aircraft is presented and the resulting optimum wing structure, cruise and jig shapes are explained in detail.

Wing Design of Supersonic Transport by a Multi-Point Optimization Method

2008

One of the difficulties in the aerodynamic design of a supersonic transport is the wing design considering both supersonic and low-speed performance. The wing with large sweepback angle and low aspect ratio is often used to reduce wave drag at supersonic cruise, but it also results in poor performance at low speeds such as take-off and landing conditions. Therefore, a large area is required for the wing to generate enough lift and, consequently reduce the take-off and landing field length. On the other hand, this also leads to an increase in aircraft weight and uneconomical flight. The purpose of this research is to propose a multipoint design method which can obtain a compromised solution of wings for a supersonic transport, by using low fidelity methods such as a combination of the Quasi-Vortex-Lattice Method and the Leading-edge Suction Analogy for high-lift device design at low-speeds, and the supersonic linear theory at supersonic speeds. The multi-point design method proposed ...