Surface triangulation for polygonal models based on CAD data

Ito, Yasushi; Nakahashi, Kazuhiro

doi:10.1002/fld.281

Cited by 172 publications

(74 citation statements)

References 8 publications

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“…12) The LU-SGS implicit method for unstructured meshes 13) is used for the time integration. Three-dimensional unstructured meshes are generated using the TAS-mesh package, which includes surface mesh generation using an advancing front approach 14,15) and tetrahedral volume mesh generation using a Delaunay approach.…”

Section: Flow Evaluationmentioning

confidence: 99%

Aerodynamic Study of Twin-Body Fuselage Configuration for Supersonic Transport

Yamazaki¹,

Kusunose²

2013

Trans. Japan Soc. Aero. S Sci.

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In this paper, a twin-body fuselage configuration is discussed for advanced supersonic transport. This twin-body fuselage concept is inspired by the wave reduction effect of the supersonic biplane airfoils proposed by Kusunose et al. The wave drag characteristics as well as the wave drag reduction are discussed by inviscid CFD computations at our design Mach number of 1.7 utilizing an aerodynamic design optimization method. Aerodynamic shape optimizations of single/twin-body fuselages are executed to explore the lowest wave drag configurations. The optimally designed non-axisymmetrical twin-body shows the best aerodynamic performance. Wave drag of our proposed twin-body shows 2/3 that of the Sears-Haack body. It is well known that the Sears-Haack (single) body has the lowest wave drag for given volume and length of the body. The increment of skin friction drag is also discussed for the twin-body fuselage configuration. Based on the total drag analysis, the superiority of the optimal twin-body fuselage configuration over the conventional single-body fuselage configuration is clearly demonstrated.

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Section: Flow Evaluationmentioning

confidence: 99%

Aerodynamic Study of Twin-Body Fuselage Configuration for Supersonic Transport

Yamazaki¹,

Kusunose²

2013

Trans. Japan Soc. Aero. S Sci.

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“…[17][18][19][20] Three types of computational meshes with different numbers of nodes (coarse: 0.807 million nodes; medium: 3.43 million nodes; fine: 10.6 million nodes) are prepared for the baseline model with the SC(2)-0518 airfoil to evaluate the grid convergence. Figure 5 shows the medium mesh of the baseline model with the SC(2)-0518 airfoil.…”

Section: Model Geometry and Flow Conditionsmentioning

confidence: 99%

Parametric Study of Vortex Generators on a Super Critical Infinite-Wing to Alleviate Shock-Induced Separation

Namura

Jeong

2013

Trans. Japan Soc. Aero. S Sci.

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A parametric study of vortex generators (VGs) on the transonic infinite-wing with two types of airfoil is performed using computational fluid dynamics to identify the effects of five parameters: height, aspect ratio, incidence angle, spacing and chord location, on the aerodynamic characteristics. First, an SC(2)-0518 airfoil with large thickness ratio and leading-edge radius is employed. The VG spacing significantly affects the shock wave location. If the spacing is narrow, the shock wave moves downstream, which increases the lift coefficient at a high angle of attack. In contrast, broad spacing suppresses the fluctuation of the pitching moment coefficients. This difference is caused by the interactions among vortices. The VG height changes the drag coefficients and is correlated with the VG spacing. The other airfoil considered is a cross-section airfoil of a NASA common research model with small thickness ratio and leading-edge radius. The spacing effect with this airfoil is almost the same as that of the SC(2)-0518 airfoil. The VG location has little influence, but the VG located more upstream would be better. In addition, an appropriate incidence angle and aspect ratio exist for generating the vortex efficiently.

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“…A flow solver named Tohoku University aerodynamic simulation code using a three-dimensional unstructured grid [24,25] was used to evaluate aerodynamic performance. In the simulation, the Euler/ Navier-Stokes equations were solved by a finite volume cell-vertex scheme.…”

Section: A Flow Solvermentioning

confidence: 99%

Three-Dimensional Aerodynamic Design of Low-Wave-Drag Supersonic Biplane Using Inverse Problem Method

Maruyama

Matsushima

Kusunose

et al. 2009

Journal of Aircraft

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In supersonic flight, airfoils generate strong sonic boom and wave drag accompanied by shock waves and expansion waves. The Busemann biplane is representative of an airfoil that has the possibility of realizing low drag. With the aim of realizing a new concept of supersonic transport, aerodynamic design and analysis are discussed based on computational fluid dynamics. Traditional biplane airfoils were extended to three-dimensional wings with a design Mach number of 1.7. Euler simulations of three-dimensional biplane wings of several configurations were conducted. Because of the existence of wing tips, three-dimensional biplane wings do not perform as well as twodimensional biplane airfoils. This is because the areas affected by Mach cones originated from the wing tips, which precludes the occurrence of an appropriate pressure wave interaction. Thus, the wing tip area has a large drag coefficient. To overcome these problems, a tapered wing is herein considered. After parametric studies, a wing planform was determined, the taper ratio and aspect ratio of which were 0.25 and 5.12, respectively. Aerodynamic design of wing section shapes of the three-dimensional tapered biplane wing was conducted using an inverse-problem method. The designed biplane wing shows a better lift-to-drag ratio performance than the two-dimensional flat-plate airfoil in the range where the lift coefficient is more than 0.17. Tapered wings were also found to have several span sections that achieve better performances than two-dimensional biplane airfoils.= friction drag coefficient of the two-dimensional airfoil in Navier-Stokes simulations C dp = pressure drag coefficient of the two-dimensional airfoil in Navier-Stokes simulations C l = lift coefficient of the two-dimensional airfoil C p = pressure coefficient c = chord of the two-dimensional airfoil c mid = position of the midchord at the wing tip of the threedimensional wing c root = chord at the wing root of the three-dimensional wing c tip = chord at the wing tip of the three-dimensional wing c 1 , c 2 = Busemann coefficients fx = airfoil geometry h = gap between two elements of the biplane L=D = lift-to-drag ratio of the three-dimensional wing l=d = lift-to-drag ratio of the two-dimensional airfoil M 1 = freestream Mach number Re = Reynolds number S = reference area t = airfoil thickness x = streamwise coordinate y = spanwise coordinate z = vertical coordinate = angle of attack = ratio of specific heats " = inclination relative to the freestream direction = df= dx- = aspect ratio

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Surface triangulation for polygonal models based on CAD data

Cited by 172 publications

References 8 publications

Aerodynamic Study of Twin-Body Fuselage Configuration for Supersonic Transport

Aerodynamic Study of Twin-Body Fuselage Configuration for Supersonic Transport

Parametric Study of Vortex Generators on a Super Critical Infinite-Wing to Alleviate Shock-Induced Separation

Three-Dimensional Aerodynamic Design of Low-Wave-Drag Supersonic Biplane Using Inverse Problem Method

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