scholarly journals AERO DYNAMIC SHAPE OF TRANSPORT AIRCRAFT “FLYING WING” SCHEME WITH HIGH ASPECT RATIO

2014 ◽  
pp. 84-92
Author(s):  
Олег Львович Лемко ◽  
Євген О. Кушніренко
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Aerodynamic Characteristics ◽  
Design Parameters ◽  
Scientific Methods ◽  
Transport Aircraft ◽  
Research Problems ◽  
And Performance ◽  
Forming Methods ◽  
Dynamic Shape

"Normal" aerodynamic scheme despite the fact that it has become the dominant in global aviation, in terms of aerodynamics is not ideal. To create a lifting force only wing is just necessary. All other elements of aircraft glider - fuselage , horizontal and vertical tail exist only for the crew, passengers and cargo, ensuring the sustainability and management to provide a satisfactory landing characteristics. It became apparent that with the increasing size of the planes becomes possible and appropriate to place all the major part of their weight directly in the wing. This idea was expressed in aerodynamic scheme "flying wing".The purpose of the research is to form aerodynamic look of transport aircraft "flying wing" scheme with high aspect ratio, creating aerodynamic design that provides the greatest rate of return and optimal weight range and flight duration.Objectives of the study are: analysis of scientific sources on establishing LA scheme "flying wing", development of forming methods of the aerodynamic look of transport aircraft scheme "flying wing", based on a synthesis of existing methods for assessing the flight - the technical characteristics of the aircraft, studies and analyzes of theoretical methods of aerodynamic layouts transport aircraft "flying wing" scheme to determine the aerodynamic and flight characteristics.            Were used following scientific methods to solve the research problems:             1. Method of forming the aerodynamic characteristics of the freeform aircraft shape in the parameters of similarity and generalized design parameters.             2. Statistical methods for assessing the aerodynamic and performance characteristics.             3. Numerical methods.The practical value of my work: developed method allows you to create aerodynamic layout scheme aircraft "flying wing" of the great extension that allows you to fully realize the benefits of the scheme, developed and reasonable advices on the aircraft aerodynamic look of "flying wing" scheme of high aspect ratio.

Static Aeroelasticity Analysis of High Aspect Ratio Wing and the Jig-Shape Design Based on Multi-Block Structural Grid

2013 ◽  
Vol 302 ◽  
pp. 377-383 ◽  
Author(s):  
Yan Liu ◽  
Jun Qiang Bai ◽  
Jun Hua
Keyword(s):  
Aspect Ratio ◽  
Design Process ◽  
High Aspect Ratio ◽  
Design Method ◽  
Aerodynamic Characteristics ◽  
Shape Design ◽  
Transport Aircraft ◽  
Mesh Motion ◽  
Static Aeroelasticity ◽  
Motion Method

The influence of structural elastic deformation on the aerodynamic characterisitcs of large transport aircraft has been researched. A method of static aeroelasticity based on multi-block structural grid of high aspect ratio wing has been established, and then a design method of jig-shape is developed. The technology of RBF interpolation is used to exchange the data of CFD/CSD. Based on RBF&Delaunay technology, a mesh motion method is developed to make the design process less time-consuming, which can be applied to large deformation of multi-block structural grid. The static aeroelastic deformation of a wing-body of large transport aircraft is analyzed. Then the wing-body's jig-shape is designed. Compared the aerodynamic characteristics between design cruise shape and target cruise shape, it shows that the aerodynamic characteristics of design cruise shape is almost equal to target cruise shape and the design process of jig-shape is feasible.

scholarly journals Pipeline Compressor Redesign With the Consideration of Both Noise and Performance

2000 ◽  
Author(s):  
Yuri I. Biba ◽  
Zheji Liu ◽  
D. Lee Hill
Keyword(s):  
High Efficiency ◽  
Aerodynamic Characteristics ◽  
The Body ◽  
Design Parameters ◽  
Original Design ◽  
Tonal Noise ◽  
Experimental Performance ◽  
Expected Performance ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance

A complete effort to redesign the aerodynamic characteristics of a single-stage pipeline compressor is presented. The components addressed are the impeller, diffuser region, and the volute. The innovation of this effort stems from the simultaneous inclusion of both the noise and aerodynamic performance as primary design parameters. The final detailed flange-to-flange analysis of the new components clearly shows that the operating range is extended and the tonal noise driven by the impeller is reduced. This is accomplished without sacrificing the existing high efficiency of the baseline machine. The body of the design effort uses both Computational Fluid Dynamics (CFD) and vibro-acoustics technology. The predictions are anchored by using the flange-to-flange analysis of the original design and its experimental performance data. By calculating delta corrections and assuming that these deltas are approximately the same for the new design, the expected performance is extrapolated.

DESIGN AND PERFORMANCE OF HARD: A HIGH-ASPECT-RATIO ITER DESIGN

1993 ◽  
pp. 1646-1650
Author(s):  
J.C. WESLEY ◽  
W. BARR ◽  
E. BOBROV ◽  
J. BROOKS ◽  
R. BULMER ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
And Performance

The effect of the high-aspect-ratio design parameters on ITER containment structures

2002 ◽  
Author(s):  
B.E. Nelson ◽  
D.L. Conner ◽  
P.J. Fogarty ◽  
G.H. Jones ◽  
D.C. Lousteau ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Design Parameters

The effect of stiffness and geometric parameters on the nonlinear aeroelastic performance of high aspect ratio wings

2016 ◽  
Vol 231 (10) ◽  
pp. 1824-1850 ◽  
Author(s):  
F Afonso ◽  
G Leal ◽  
J Vale ◽  
É Oliveira ◽  
F Lau ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Nonlinear Behavior ◽  
Geometric Parameters ◽  
Torsional Stiffness ◽  
Design Parameters ◽  
Sweep Angle ◽  
Flutter Speed ◽  
Wing Model ◽  
Aspect Ratios

The increase in wing aspect ratio is gaining interest among aircraft designers in conventional and joined-wing configurations due to the higher lift-to-drag ratios and longer ranges. However, current transport aircraft have relatively small aspect ratios due their increased structural stiffness. The more flexible the wing is more prone to higher deflections under the same operating condition, which may result in a geometrical nonlinear behavior. This nonlinear effect can lead to the occurrence of aeroelastic instabilities such as flutter sooner than in an equivalent stiffer wing. In this work, the effect of important stiffness (inertia ratio and torsional stiffness) and geometric (sweep and dihedral angles) design parameters on aeroelastic performance of a rectangular high aspect ratio wing model is assessed. The torsional stiffness was observed to present a higher influence on the flutter speed than the inertia ratio. Here, the decrease of the inertia ratio and the increase of the torsional stiffness results in higher flutter and divergence speeds. With respect to the geometric parameters, it was observed that neither the sweep angle nor the dihedral angle variations caused a substantial influence on the flutter speed, which is mainly supported by the resulting smaller variations in torsion and bending stiffness due to the geometric changes.

Body Freedom Flutter Study and Passive Flutter Suppression for a High Aspect Ratio Flying Wing Model

2014 ◽  
Vol 608-609 ◽  
pp. 708-712 ◽  
Author(s):  
Yuan Dong Li ◽  
Xin Ping Zhang ◽  
Ying Song Gu ◽  
Zhi Chun Yang
Keyword(s):  
Aspect Ratio ◽  
Mass Balance ◽  
High Aspect Ratio ◽  
Center Of Gravity ◽  
The Body ◽  
Design Parameters ◽  
Wing Model ◽  
Design Variables ◽  
Optimization Study ◽  
Tip Mass

Normal mode and flutter analysis are conducted for a high aspect ratio aft swept flying wing model, and body freedom flutter is found to be the most critical aeroelastic instability for this air vehicle model. To determine the influence of various kinds of design parameters on BFF characteristics, eight factors are considered in the parametric study, i.e. wing vertical bending stiffness, weight and center of gravity of the wing root payload and the wing tip mass balance, wing half span, aft swept angle and the station of wing body blended line. After the parametric analysis, the mass and center of gravity of the wing root payload are selected as design variables, and the baseline model is utilized in the design optimization study subject to critical flutter speed constraint. Finally, the optimal mass balance design is suggested to suppress the body freedom flutter phenomenon passively and maximize the payload.

The aeroelastic characteristics of high aspect ratio wing

2016 ◽  
Vol 230 (14) ◽  
pp. 2543-2556
Author(s):  
Fan Yang ◽  
Zhufeng Yue ◽  
Lei Li
Keyword(s):  
Aspect Ratio ◽  
Large Deformation ◽  
High Aspect Ratio ◽  
Data Exchange ◽  
Stokes Equations ◽  
Great Influence ◽  
Aerodynamic Characteristics ◽  
Interface Problem ◽  
Numerical Result ◽  
Computational Structural Mechanics

Owing to the elasticity, the large deformation was brought in the high aspect ratio wing in the flight. The large deformation had a great influence on the flight performance. In this paper, the loosely coupled method was used for the research of high aspect ratio wing aeroelastic problems. The Navier–Stokes equations were solved for fluid domain computation, and the nonlinear finite element method was adopted for solid domain computation. The data exchange program and mesh regeneration progress were adopted for fluid–structure interface problem. Finally, the aerodynamic characteristics of high aspect ratio wing were obtained under different fly conditions. In addition, to validate the proposed method, the flutter analysis of AGARD 445.6 wing is carried out and compared with the experimental data. The numerical result validates the proposed computational fluid dynamics/computational structural mechanics method.

Topology Optimization of High Aspect Ratio Internal Cooling Channels As a Design for Additive Manufacturing

2020 ◽  
Author(s):  
Shinjan Ghosh ◽  
Jayanta S. Kapat
Keyword(s):  
Heat Transfer ◽  
Topology Optimization ◽  
Additive Manufacturing ◽  
Aspect Ratio ◽  
Gas Turbine ◽  
High Aspect Ratio ◽  
Design Parameters ◽  
Internal Cooling ◽  
Computational Domain ◽  
Pin Fin

Abstract High aspect ratio channels are a common internal cooling feature in Gas Turbine blades, mostly suitable for the trailing edge region or mid-chord regions. Traditionally such channels are fitted with rib-turbulators and/or pin-fin turbulators to augment heat transfer and prevent material failure. Highly efficient internal cooling of blades can improve the efficiency of a real Gas Turbine power cycle by tolerating higher Turbine Inlet Temperatures (TIT). Multi-physics Topology optimization (TO) has been employed in the current study to find optimized shape of these ducts, with an aim to increase heat transfer, while constraining the pressure drop across the channel. This method, commonly used in structural problems, is a novel topic of research when applied to fluid-thermal studies. Material distribution in the computational domain is varied by changing porosity value in each cell and thereby altering the fluid path and creating a conjugate heat transfer problem. Each cell has a value of Brinkmann porosity factor which either simulates a blockage, or a fluid region depending on a low or high value of this design variable. Hence the degree of freedom is high in this method, and there is no manual bias introduced, unlike in parametric shape optimization which is limited to a few design parameters. The unconventional geometries obtained as an end product of this optimization process can thus be an alternative to existing rib/pin-fin type of cooling geometries. The recent progress in additive manufacturing can now facilitate the manufacturing of complicated shapes. An in-house Open-FOAM solver has been used to carry out the process in only twice the amount of time compared to a regular RANS-CFD. 3-Dimensional rectangular channels with inlet aspect ratios of 4:1 and 8:1 have been considered as baselines with a constant inlet velocity. Resulting optimum geometries were found to have organic tree like branching arrangements of rib-like wall roughness and v-shaped structures.

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