Accession Number:

ADP002946

Title:

Artificial Mass Concept and Transonic Viscous Flow Equation,

Descriptive Note:

Corporate Author:

TEXAS UNIV AT AUSTIN DEPT OF AEROSPACE ENGINEERING AND ENGINEERING MECHANICS

Personal Author(s):

• Dulikravich,G. S.
• Niederdrenk,P.

Report Date:

1984-02-01

Pagination or Media Count:

10.0

Abstract:

By varying the grid clustering on the surface of an airfoil, it was observed that symmetric shocked solutions develop with a nonunique shock strength and location when numerically solving the full potential equation. It is shown analytically that the conventional form of artificial density or viscosity produces a number of truly nonlinear terms which are suspected to be the cause of the nonuniqueness for all the finite grid sizes. A concept of artificial mass flow is shown to be suitable for analytically evaluating a new exact form of the switching function that eliminates all the nonlinear terms for any value of the local Mach number. The resulting expanded full potential equation then becomes a third order partial differential equation of permanently parabolic type resembling Sichels transonic viscous flow equation. Consequently, our expanded full potential equation does not require the introduction of the customarily-used artificial time concept. Author

Descriptors:

• *Transonic flow
• *Viscous flow
• Mathematical models
• Potential flow
• Partial differential equations
• Airfoils
• Shock
• Mass
• Numerical methods and procedures
• Taylors series
• Mass flow
• Grids
• Clustering
• West Germany

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE