Direct Numerical Simulation of Three-dimensional Flow Around a Delta Wing
Author : H. Shan
Publisher :
Page : pages
File Size : 12,82 MB
Release : 2000
Category :
ISBN :
Author : H. Shan
Publisher :
Page : pages
File Size : 12,82 MB
Release : 2000
Category :
ISBN :
Author : H. Shan
Publisher :
Page : 22 pages
File Size : 28,85 MB
Release : 2001
Category :
ISBN :
The three-dimensional separated flow around a slender flat-plate delta wing with sharp leading-edge at a 12.5 deg angle of attack has been studied by solving the full compressible Navier-Stokes equations in the generalized curvilinear coordinates. The time integration is carried out by using the second-order LU-SGS implicit scheme. A fourth-order centered compact difference scheme is used for spatial derivatives. A sixth-order implicit filter is employed to reduce numerical oscillation. Non-reflecting boundary conditions are imposed at the far-field and outlet boundaries to avoid possible non-physical wave reflection. Parallel computing based on Message Passing Interface (MPI) has been utilized to improve the performance of the code. Two Reynolds numbers have been selected. At a lower Reynolds number of 50000 based on the chord length and the freestream velocity, the flow is stable and dominated by a pair of leading edge primary vortices. At a higher Reynolds number of 196000, the small-scale vortex shedding is observed near the leading-edge of the delta wing. The computational results are compared with the experimental work of Riley & Lowson (1998). The periodic shedding of small-scale vortical structures near the leading-edge has been studied in detail, and the vortex shedding is found to be associated with the Kelvin-Helmholtz-type instability and the secondary vortex. The period of vortex shedding is obtained from the time series of the three velocity components recorded near the leading-edge. The time-averaged features of the vortical structures are also discussed.
Author : Raymond E. Gordnier
Publisher :
Page : 50 pages
File Size : 25,89 MB
Release : 1993
Category : Airplanes
ISBN :
This report presents computations of the flowfield around an 80 degree sweep delta wing undergoing a constant roll-rate maneuver from 0 to 45 degrees. The governing equations for the problem are the unsteady, three- dimensional Navier-Stokes equations. The equations are solved using the implicit, approximately-factored algorithm of Beam-Warming. Fixed roll angle results are also presented and compared with experimental measurements to demonstrate the ability of the numerical technique to accurately capture the flowfield around a rolled delta wing. The dynamic behaviors of the vortex position and strength, as well as their corresponding effect on surface pressure, lift and roll moment, are described. A simple, quasi-static explanation of these vortex behaviors based on effective angle-of-attack and sideslip angle is proposed ... Delta wing roll, Vortex dynamics, Vortical flow, Unsteady maneuver.
Author : Horst Körner
Publisher : Springer Science & Business Media
Page : 438 pages
File Size : 14,79 MB
Release : 2013-04-17
Category : Technology & Engineering
ISBN : 3322865738
This volume contains the papers of the 10th AG STAB (German Aerospace Aerodynamics Association). In this association all those scientists and engineers from universities, research-establishments and industry are involved, who are doing research and project work in numerical and experimental fluid mechanics and aerodynamics for aerospace and other applications. Many of the contributions are giving first results from the "Luftfahrtforschungsprogramm der Bundesregierung (German Aeronautical Research Program) 1995-1998". Some of the papers report on work sponsored by the Deutsche Forschungsgemeinschaft, DFG, which also was presented at the symposium. The volume gives a broad overview over the ongoing work in this field in Germany.
Author : George S. Diewert
Publisher :
Page : 20 pages
File Size : 15,63 MB
Release : 1985
Category :
ISBN :
Author : Wolfgang Nitsche
Publisher : Springer Science & Business Media
Page : 550 pages
File Size : 20,15 MB
Release : 2013-11-11
Category : Mathematics
ISBN : 3663109011
This volume contains the papers of the 11th Symposium of the AG STAB (German Aerospace Aerodynamics Association). In this association those scientists and engineers from universities, research-establishments and industry are involved, who are doing research and project work in numerical and experimental fluid mechanics and aerodynamics for aerospace and other applications. Many of the contributions are giving results from the "Luftfahrtforschungsprogramm der Bundesregierung (German Aeronautical Research Programme). Some of the papers report on work sponsored by the Deutsche Forschungsgemeinschaft, DFG, which also was presented at the symposium. The volume gives a broad overview over the ongoing work in this field in Germany.
Author :
Publisher :
Page : 610 pages
File Size : 25,9 MB
Release : 2004
Category : Fluid dynamics
ISBN :
Author : Gary N. Coleman
Publisher :
Page : pages
File Size : 25,80 MB
Release : 1996
Category :
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Author :
Publisher :
Page : 380 pages
File Size : 19,79 MB
Release : 1995
Category : Aeronautics
ISBN :
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Author :
Publisher :
Page : 0 pages
File Size : 19,49 MB
Release : 1999
Category :
ISBN :
An oblique transition process of a flat-plate boundary layer at a free-stream Mach number of M (infinity) =4.5 and a Reynolds number of 10000 based on free-stream velocity and inflow displacement thickness is simulated as the validation of the code. Four transitional stages are observed: the linear and weakly nonlinear growth, the appearance of staggered A-vortex patterns, the evolution of A-vortex into hairpin vortex, the breakdown of hairpin vortical structures. The evolution of averaged quantities, such as the skin-friction coefficient, the mean velocity profile, the boundary layer thickness are all computed and found agreed very well with theoretic and experimental results. For complex geometry, 2D and 3D numerical grid generation method are used to generate high-quality meshes. Subsonic flow around 2D NACA 0012 airfoil and 3D Delta wing with a large angle of attack are investigated with large eddy simulation. Flow separations and large eddy structures are observed, the interactions between vortical structures will be studied.