Analysis of a stepwise numerical method for solution of a three-dimensional flow problem

Analysis of a stepwise numerical method for solution of a three-dimensional flow problem

Traas, C.R.

National Aerospace Laboratory NLR

1975-09-25

The simulation of a class of three-dimensional, stationary, supersonic gas flows by construction of an approximate solution to the governing system of partial differential equations, is analysed. The investigated method is a hybrid one: it involves finite difference calculations on a regular, orthogonal grid, and characteristics calculations, the latter along the boundaries of the computational region. Alternative boundary treatment methods are studied for comparison. The convergence and stability properties of the used difference scheme are analysed in depth and its dispersive and dissipative properties are examined in detail. About the influences that non-linearities may have a few statements are made. The choice of the applied difference scheme, based originally on empirical evidence from literature, is justified on the basis of a nonhnear analysis. The controversy shock capturing/shock fitting is discussed. Computational examples are given for rather complicated flow patterns, using both approaches. A smoothing method is proposed to suppress an occurring instability. It is proved that the convergence property of the difference approximation is not destroyed when the smoothing technique is applied. Finally an appraisal is given of the used computational method.

http://resolver.tudelft.nl/uuid:09181eb2-3a16-4630-a5e0-69e9d37c628b

Nationaal Lucht- en Ruimtevaartlaboratorium

Campus only

NLR-TR 75072 U

Aerospace Engineering Reports

report

(c)1975 National Aerospace Laboratory NLR