Pseudounsteady systems for steady inviscid flows
Abstract
The first order partial differential equations of pseudounsteady type for the calculation of steady inviscid flows, compressible and isoenergetic, or incompressible, were studied. A family of such systems depending on five parameters is considered. The condition for a system to be hyperbolic with respect to time, and a condition relating to the number of eigenvalues of same given sign, are discussed as a function of these parameters. Examples of pseudounsteady systems are given, showing the very varied properties which these systems possess. There exist systems which are optimal with regard to an explicit numerical stability criterion. In flows which either are homentropic for a compressible fluid, or have uniform total pressure for an incompressible fluid, a two parameter family of simpler pseudounsteady systems is shown to exist.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 November 1984
 Bibcode:
 1984STIN...8525782V
 Keywords:

 Compressible Flow;
 Partial Differential Equations;
 Steady Flow;
 Eigenvalues;
 Euler Equations Of Motion;
 Hyperbolic Functions;
 Inviscid Flow;
 Isoenergetic Processes;
 Fluid Mechanics and Heat Transfer