Accession Number:

ADP013654

Title:

Adaptive Numerical-Dissipation/Filter Controls for High Order Numerical Methods

Descriptive Note:

Conference paper

Corporate Author:

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION MOFFETT FIELD CA AMES RESEARCHCENTER

Personal Author(s):

Report Date:

2001-08-01

Pagination or Media Count:

16.0

Abstract:

Proper control of the numerical-dissipationfilter to accurately resolve all relevant multiscales of complex flow problems while still maintaining nonlinear stability and efficiency for long-time numerical integrations poses a great challenge to the design of numerical methods. The required type and amount of numerical-dissipationfilter are not only physical problem dependent but also vary from one flow region to another. An approach for the automatic detection of different flow features as distinct sensors to signal the appropriate type and amount of numerical-dissipationfilter for non-dissipative high order schemes is proposed. These scheme-independent sensors are capable of distinguishing shocksshears, turbulent fluctuations and spurious high frequency oscillations. In addition, these sensors are readily available as an improvement over existing grid adaptation indicators. The same shockshear detector that is designed to switch on the shockshear numerical dissipation can be used to switch off the entropy splitting form of the inviscid flux derivative in the vicinity the discontinuous regions to further improve nonlinear stability and minimize the use of numerical dissipation. The rest of the sensors in conjunction with the local flow speed and Reynolds number can also be used to adaptively determine the appropriate entropy splitting parameter for each flow typeregion. The goal of this paper is to further improve nonlinear stability, accuracy and efficiency of long-time numerical integration of complex shockturbulenceacoustics interactions and numerical combustion. The minimization of employing very fine grids to overcome the production of spurious numerical solution andor instability due to under-resolved grids is also sought.

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE