Accession Number:

ADA179706

Title:

Unsteady Boundary Layers with an Intelligent Numerical Scheme.

Descriptive Note:

Final rept.,

Corporate Author:

DOUGLAS AIRCRAFT CO LONG BEACH CA

Personal Author(s):

Report Date:

1984-11-01

Pagination or Media Count:

25.0

Abstract:

A numerical method has been developed to represent unsteady boundary layers with large flow reversal. It makes use of the characteristic box scheme which examines the finite-difference grid in relation to the magnitude and direction of local velocity and reaches and implements a decision to ensure that the Raetz principle of regions of influence and dependence is not violated. The method has been applied to the problem of an impulsively started circular cylinder and the results though generally consistent with those of van Dommelen and Shen obtained with a Lagrangian method, show some differences. The time step is identified as very important and, with the present intelligent numerical scheme, the results were readily extended to times far beyond those previously achieved with Eulerian methods. Extrapolation of the results suggests that the much discussed singularity for this unsteady flow is the same as that of the corresponding steady flow.

Subject Categories:

  • Fluid Mechanics
  • Numerical Mathematics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE