Results 1  10
of
12
The present status, challenges, and future developments in Computational Fluid Dynamics
 77th AGARD Fluid Dynamics Panel Symposium
, 1995
"... This paper presents a perspective on corn utational fluid dynamics as a tool for aircraft desi t addresses the requirements for effective industriaf%e,.and tradeoffs between modelling accuracy and computational costs. Issues in algorithmaesi ari discussed in detail, together with a unified,ap roac ..."
Abstract

Cited by 8 (2 self)
 Add to MetaCart
This paper presents a perspective on corn utational fluid dynamics as a tool for aircraft desi t addresses the requirements for effective industriaf%e,.and tradeoffs between modelling accuracy and computational costs. Issues in algorithmaesi ari discussed in detail, together with a unified,ap roac 8 " to the design of shock captunng algonthms. Fin aYly, the pa r discusses the use of techniouec drawn from... ~~ controf%eow, to detemune ootimal aerodynamic shapes. In the future mul$disclplinaj analysis and optimization should be combined to provide an integratednumerical design environment. 2.
Approximate And Incomplete Factorizations
 ICASE/LARC INTERDISCIPLINARY SERIES IN SCIENCE AND ENGINEERING
, 1994
"... In this chapter, we give a brief overview of a particular class of preconditioners known as incomplete factorizations. They can be thought of as approximating the exact LU factorization of a given matrix A (e.g. computed via Gaussian elimination) by disallowing certain fillins. As opposed to other ..."
Abstract

Cited by 5 (2 self)
 Add to MetaCart
In this chapter, we give a brief overview of a particular class of preconditioners known as incomplete factorizations. They can be thought of as approximating the exact LU factorization of a given matrix A (e.g. computed via Gaussian elimination) by disallowing certain fillins. As opposed to other PDEbased preconditioners such as multigrid and domain decomposition, this class of preconditioners are primarily algebraic in nature and can in principle be applied to any sparse matrices. When applied to PDE problems, they are usually not optimal in the sense that the condition number of the preconditioned system will grow as the mesh size h is reduced, although usually at a slower rate than for the unpreconditioned system. On the other hand, they are often quite robust with respect to other more algebraic features of the problem such as rough and anisotropic coefficients and strong convection terms. We will describe the basic ILU and (modified) MILU preconditioners. Then we will review ...
A Multigrid Block LUSGS Algorithm for Euler Equations on Unstructured Grids
, 2007
"... We proposed an efficient and robust algorithm to solve the steady Euler equations on unstructured grids. The new algorithm is a Newtoniteration method in which every iteration step is a linear multigrid method using block lowerupper symmetric GaussSeidel (LUSGS) iteration as its smoother. To reg ..."
Abstract

Cited by 1 (1 self)
 Add to MetaCart
(Show Context)
We proposed an efficient and robust algorithm to solve the steady Euler equations on unstructured grids. The new algorithm is a Newtoniteration method in which every iteration step is a linear multigrid method using block lowerupper symmetric GaussSeidel (LUSGS) iteration as its smoother. To regularize the Jacobian matrix of Newtoniteration, we adopted a local residual dependent regularization, as the replacement of the standard timestepping relaxation technique based on the local CFL number. The proposed method can be extended to high order approximations and three spatial dimensions in a nature way. The solver was tested on a sequence of benchmark problems on both quasiuniform and local adaptive meshes. Fruitful numerical results illustrated the efficiency and robustness of our algorithm.
The Origins and Further Development of the JamesonSchmidtTurkel (JST) Scheme
"... This paper is in response to an invitation to give a presentation on the origins and subsequent development of the JamesonSchmidtTurkel scheme. After a description of the historical background and initial development of the scheme, the paper discusses three main developments: first, the developmen ..."
Abstract
 Add to MetaCart
(Show Context)
This paper is in response to an invitation to give a presentation on the origins and subsequent development of the JamesonSchmidtTurkel scheme. After a description of the historical background and initial development of the scheme, the paper discusses three main developments: first, the development of convergence acceleration methods, including residual averaging and multigrid; second, the extension to unstructured grids; and third the reformulation of the JST scheme as a total variation diminishing (TVD) scheme, and its relationship to symmetric TVD schemes. The paper concludes with a brief review of applications to unsteady and viscous flows. I.
NUMERICAL SIMULATION OF SUPERSONIC FLOW AROUND WINGBODY CONFIGURATION WITH INTEGRATED ENGINE NACELLE
"... This paper presents numerical simulation of flowfields around a supersonic transport aircraft with an integrated engine nacelle. In this study, flowfields were simulated by solving the Euler equations with the unstructured grid method for handling the complex geometry. To simulate intake flows at ac ..."
Abstract
 Add to MetaCart
(Show Context)
This paper presents numerical simulation of flowfields around a supersonic transport aircraft with an integrated engine nacelle. In this study, flowfields were simulated by solving the Euler equations with the unstructured grid method for handling the complex geometry. To simulate intake flows at actual flights, a bump was introduced inside the nacelle. The effect of nacelle mass flow ratios on overall aerodynamic performance was investigated in detail by changing bump heights. The spillage drag was calculated and found to have a large impact on the total drag. Computed results were compared with wind tunnel data obtained at National Aerospace Laboratory of Japan. 1.
unknown title
"... Assessment of implicit operators for the upwind point GaussSeidel method on unstructured meshes ..."
Abstract
 Add to MetaCart
(Show Context)
Assessment of implicit operators for the upwind point GaussSeidel method on unstructured meshes
LU Implicit Scheues with Bultiple Grids for the Euler Equation
"... An LU iuplicit acheue ia developed for the The uoat aucceaaful implicit acheue (baaed unateadv Euler equations. It is proved on the efficiencv and the accuracv> of that a aymuetric aucceaaive overrelaxation residual averaging type eo far haa been uethod for solving the unfectored implicit 6 Jaus ..."
Abstract
 Add to MetaCart
An LU iuplicit acheue ia developed for the The uoat aucceaaful implicit acheue (baaed unateadv Euler equations. It is proved on the efficiencv and the accuracv> of that a aymuetric aucceaaive overrelaxation residual averaging type eo far haa been uethod for solving the unfectored implicit 6 Jausson’a uultietage scheme. echeue id equivalent to a modified form of the LU iuplicit scheue. A uultigrid method is developed for the LU iuplicit scheue to Iuplicit acheaee of approximate produce a rapidly convergent algorithm for factorization type are ettrective becauee calculating steady state solutions of the they are expected to be very uaeful in Euler equations.
Computation Of Steady Flow In A Turbomachinery Stage By A ThirdOrder Accurate HighResolution Scheme
"... This paper extends a thirdorder accurate ENO scheme with implicit LUSGS timestepping to calculate flow in a multiple blade row environment. The flow is considered steady relative to each blade row individually and the rows communicate via interbladerow mixing planes. The interbladerow mixing p ..."
Abstract
 Add to MetaCart
This paper extends a thirdorder accurate ENO scheme with implicit LUSGS timestepping to calculate flow in a multiple blade row environment. The flow is considered steady relative to each blade row individually and the rows communicate via interbladerow mixing planes. The interbladerow mixing plane introduces circumferential averaging of flow properties but preserves spanwise variations. The flows through a turbine stage and a compressor stage are calculated. Comparisons between numerical results and measurements are provided. 1 Introduction As the performance of turbomachines steadily improves, designers become more and more interested in flow predictions of blade rows in a multistage environment, rather than traditional singleblade row calculations. In the calculation of flow in an isolated blade row, proper inflow and outflow conditions must be specified before the calculation. These conditions are usually taken from a multistage throughflow calculation, which, however, may...