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Sergei V. Udin - One of the best experts on this subject based on the ideXlab platform.
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Wing Mass Formula for Twin Fuselage Aircraft
2016Co-Authors: Sergei V. Udin, William J. AndersontAbstract:A formula is derived to calculate structural Wing mass. This formula can be applied to twin fuselage aircraft, conventional single-body aircraft and some other unconventional aircraft (such as the Voyager). The approach is particularly useful in the first stages of preliminary aircraft design and in optimization programs where the Wing-mass calculation time is an important characteristic. The concept model assumes a nontapered Inboard Wing section, a tapered outboard Wing section and fuel stored only in the outboard Wing. The theory for the Wing-mass estimation is described. Unlike the other mass formulae where mass spanwise distribution is considered by an "unloading coefficient, " the present method integrates the mass spanwise distribution with the air load spanwise distribution. This allows more precise consideration of the Wing geometry and mass unloading. There are no simplifications applied and the formula completely reflects the initial concept model. Good comparison with statistical data for single body aircraft is obtained. Nomenclature A — aspect ratio a = gravitational acceleration b = Wing span c = Wing chor
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Wing mass formula for twin fuselage aircraft
Journal of Aircraft, 1992Co-Authors: Sergei V. Udin, William J. AndersonAbstract:A formula is derived to calculate structural Wing mass. This formula can be applied to twin fuselage aircraft, conventional single-body aircraft and some other unconventional aircraft (such as the Voyager). The approach is particularly useful in the first stages of preliminary aircraft design and in optimization programs where the Wing-mass calculation time is an important characteristic. The concept model assumes a nontapered Inboard Wing section, a tapered outboard Wing section and fuel stored only in the outboard Wing. The theory for the Wing-mass estimation is described. Unlike the other mass formulae where mass spanwise distribution is considered by an "unloading coefficient," the present method integrates the mass spanwise distribution with the air load spanwise distribution. This allows more precise consideration of the Wing geometry and mass unloading. There are no simplifications applied and the formula completely reflects the initial concept model. Good comparison with statistical data for single body aircraft is obtained.
J. Schetz - One of the best experts on this subject based on the ideXlab platform.
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A Numerical and Experimental Aerodynamic Analysis of an Inboard-Wing/Twin-Fuselage Configuration
19th AIAA Applied Aerodynamics Conference, 2001Co-Authors: Z. Wang, S. Magill, S. Preidikman, D. Mook, J. SchetzAbstract:In this paper, we present and compare numerical and experimental studies of the flowfield around a configuration consisting of an Inboard Wing mounted between twin fuselages. The results of both studies show that behind the doublefuselage configuration a "virtual Wing-tip vortex system" forms. The trailing vortex system for the twin-fuselage configuration is shed from both the fuselages as well as the trailing edge of the Wing. The vorticity shed from the fuselages combines with the vorticity from the trailing edge in a manner that is very similar to what happens in a conventional single-fuselage configuration. The numerical and experimental results are in qualitative agreement. Introduction The aviation industry has been urged to develop faster and/or bigger airplanes and to fly them closer together as part of a large effort to meet the needs of an ever-increasing air transportation system. One of the innovative ideas for a large airplane comes from the NASA Langley Research Center. Spearman and Feigh suggested a configuration that differs from a conventional Wing-body-tail design. Instead of one fuselage located in the center of the configuration, twin fuselages are placed at the tips of an Inboard Wing. The intent is "to provide an increase in payload capacity without an increase Graduate Research Assistant Currently Prof., Univ. Nacional, Rio Cuarto, Argentina N. Waldo Harrison Prof., Assoc. Fellow AIAA Fred D. Durham Chair, Fellow AIAA Copyright© American Institute of Aeronautics And Astronautics, All Rights Reserved in overall length and width when compared to current designs and to achieve two-dimensional flow on the Wing by eliminating free Wing tips so that the Wing tip flow that produces an induced drag and a hazardous trailing vortex would not exist." One aerodynamic model' has been tested in Virginia Tech's Stability Wind Tunnel to study this Inboard-Wing, twin-fuselage concept. The configuration is represented schematically in Figure 1. In addition, the configuration represented in Figure 1 has been modeled aerodynamically. Here we present some comparisons between the numerical and experimental data and respond to some of Spearman's and Feigh's comments. To model the flowfield, we use (1) the wellknown code PMARC, ignoring the deformations of the wake but accounting for the aerodynamic interference, and (2) the general unsteady vortex-lattice method (VLM), accounting for the deformations of the wakes and the aerodynamic interference among the various components of the configuration. The version of VLM that we use in this work has been developed at Virginia Tech over several years 16 to solve for the incompressible flow over both lifting and nonlifting bodies. The method utilizes a lattice of discrete vortex lines distributed over the surfaces of the configuration. The circulations around the discrete vortex segments are obtained by imposing the no-penetration condition on the body surfaces. Imposing the unsteady "Kutta condition" along the edges where separation occurs provides the vorticity-shedding rate, and convecting the vorticity in the wake with the local particle velocity renders the wake forcefree. The advantages of this method are that it also satisfies the no-slip condition and readily provides the surface velocity and pressure, and it
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a numerical and experimental aerodynamic analysis of an Inboard Wing twin fuselage configuration
19th AIAA Applied Aerodynamics Conference, 2001Co-Authors: Z. Wang, S. Magill, S. Preidikman, D. Mook, J. SchetzAbstract:In this paper, we present and compare numerical and experimental studies of the flowfield around a configuration consisting of an Inboard Wing mounted between twin fuselages. The results of both studies show that behind the doublefuselage configuration a "virtual Wing-tip vortex system" forms. The trailing vortex system for the twin-fuselage configuration is shed from both the fuselages as well as the trailing edge of the Wing. The vorticity shed from the fuselages combines with the vorticity from the trailing edge in a manner that is very similar to what happens in a conventional single-fuselage configuration. The numerical and experimental results are in qualitative agreement. Introduction The aviation industry has been urged to develop faster and/or bigger airplanes and to fly them closer together as part of a large effort to meet the needs of an ever-increasing air transportation system. One of the innovative ideas for a large airplane comes from the NASA Langley Research Center. Spearman and Feigh suggested a configuration that differs from a conventional Wing-body-tail design. Instead of one fuselage located in the center of the configuration, twin fuselages are placed at the tips of an Inboard Wing. The intent is "to provide an increase in payload capacity without an increase Graduate Research Assistant Currently Prof., Univ. Nacional, Rio Cuarto, Argentina N. Waldo Harrison Prof., Assoc. Fellow AIAA Fred D. Durham Chair, Fellow AIAA Copyright© American Institute of Aeronautics And Astronautics, All Rights Reserved in overall length and width when compared to current designs and to achieve two-dimensional flow on the Wing by eliminating free Wing tips so that the Wing tip flow that produces an induced drag and a hazardous trailing vortex would not exist." One aerodynamic model' has been tested in Virginia Tech's Stability Wind Tunnel to study this Inboard-Wing, twin-fuselage concept. The configuration is represented schematically in Figure 1. In addition, the configuration represented in Figure 1 has been modeled aerodynamically. Here we present some comparisons between the numerical and experimental data and respond to some of Spearman's and Feigh's comments. To model the flowfield, we use (1) the wellknown code PMARC, ignoring the deformations of the wake but accounting for the aerodynamic interference, and (2) the general unsteady vortex-lattice method (VLM), accounting for the deformations of the wakes and the aerodynamic interference among the various components of the configuration. The version of VLM that we use in this work has been developed at Virginia Tech over several years 16 to solve for the incompressible flow over both lifting and nonlifting bodies. The method utilizes a lattice of discrete vortex lines distributed over the surfaces of the configuration. The circulations around the discrete vortex segments are obtained by imposing the no-penetration condition on the body surfaces. Imposing the unsteady "Kutta condition" along the edges where separation occurs provides the vorticity-shedding rate, and convecting the vorticity in the wake with the local particle velocity renders the wake forcefree. The advantages of this method are that it also satisfies the no-slip condition and readily provides the surface velocity and pressure, and it
Kazuhiro Nakahashi - One of the best experts on this subject based on the ideXlab platform.
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Multi-Point Design of Wing-Body-Nacelle-Pylon Configuration
24th AIAA Applied Aerodynamics Conference, 2006Co-Authors: Takashi Saitoh, Hyoung-jin Kim, Keizo Takenaka, Kazuhiro NakahashiAbstract:Aerodynamic design optimization is conducted for DLR-F6 Wing-body-nacelle-pylon configuration adopting an efficient surface mesh movement method. A three-dimensional unstructured Euler solver and its discrete adjoint code are utilized for flow and sensitivity analysis, respectively. Two design conditions considered are a low-lift condition and a cruise condition in transonic regime. Design objective is to minimize drag and reduce shock strength at both flow conditions. Shape deformation is made by variation of the section shapes of Inboard Wing and pylon, nacelle vertical location and nacelle pitch angle. Hicks-Henne shape functions are employed for deformation of the section shapes of Wing and pylon. Design iterations converged to obtain drag coefficients remarkably reduced at both design conditions retaining specified lift coefficient and satisfying constraints. Two-point design results show mixed features of the one-point design results at low-lift condition and cruise conditions.
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Aerodynamic Design of Wing-Body-Nacelle-Pylon Configuration
17th AIAA Computational Fluid Dynamics Conference, 2005Co-Authors: Salim Koc, Hyoung Kim, Kazuhiro NakahashiAbstract:Aerodynamic design optimization is conducted for DLR-F6 Wing-body-nacelle-pylon configuration adopting an efficient surface mesh movement method. A three-dimensional unstructured Euler solver and its discrete adjoint code are utilized for flow and sensitivity analysis respectively. The design objective is to minimize drag and reduce shock strength on pylon surface to decrease buffet risk at a climb condition. Shape deformation is made by variation of Inboard Wing and pylon section shape, nacelle vertical location and nacelle pitch angle. Hicks-Henne shape functions are adopted for the Inboard Wing shape and pylon shape perturbation. Totally 82 design variables are defined. Four design constraints are considered in the optimizer, three for Wing section and one for pylon section maximum thickness. Lift constraint and Mach number constraint on pylon surface are satisfied by adding relevant penalty terms to the objective function. Design iterations converged to obtain a drag coefficient reduced by 16 counts retaining specified lift coefficient and satisfying the constraints. Shock wave strength around pylon surface was remarkably reduced by the design. The successful design results validate effectiveness and efficiency of the present design approach.
William J. Anderson - One of the best experts on this subject based on the ideXlab platform.
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Wing mass formula for twin fuselage aircraft
Journal of Aircraft, 1992Co-Authors: Sergei V. Udin, William J. AndersonAbstract:A formula is derived to calculate structural Wing mass. This formula can be applied to twin fuselage aircraft, conventional single-body aircraft and some other unconventional aircraft (such as the Voyager). The approach is particularly useful in the first stages of preliminary aircraft design and in optimization programs where the Wing-mass calculation time is an important characteristic. The concept model assumes a nontapered Inboard Wing section, a tapered outboard Wing section and fuel stored only in the outboard Wing. The theory for the Wing-mass estimation is described. Unlike the other mass formulae where mass spanwise distribution is considered by an "unloading coefficient," the present method integrates the mass spanwise distribution with the air load spanwise distribution. This allows more precise consideration of the Wing geometry and mass unloading. There are no simplifications applied and the formula completely reflects the initial concept model. Good comparison with statistical data for single body aircraft is obtained.
William J. Andersont - One of the best experts on this subject based on the ideXlab platform.
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Wing Mass Formula for Twin Fuselage Aircraft
2016Co-Authors: Sergei V. Udin, William J. AndersontAbstract:A formula is derived to calculate structural Wing mass. This formula can be applied to twin fuselage aircraft, conventional single-body aircraft and some other unconventional aircraft (such as the Voyager). The approach is particularly useful in the first stages of preliminary aircraft design and in optimization programs where the Wing-mass calculation time is an important characteristic. The concept model assumes a nontapered Inboard Wing section, a tapered outboard Wing section and fuel stored only in the outboard Wing. The theory for the Wing-mass estimation is described. Unlike the other mass formulae where mass spanwise distribution is considered by an "unloading coefficient, " the present method integrates the mass spanwise distribution with the air load spanwise distribution. This allows more precise consideration of the Wing geometry and mass unloading. There are no simplifications applied and the formula completely reflects the initial concept model. Good comparison with statistical data for single body aircraft is obtained. Nomenclature A — aspect ratio a = gravitational acceleration b = Wing span c = Wing chor
