Title: Navier–Stokes Characteristic Boundary Conditions Using Ghost Cells

Abstract

Solution methods for the compressible Navier–Stokes equations based on finite volume discretizations often implement boundary conditions using ghost cells outside of the computational domain. Filling the ghost cells using straightforward zeroth-or first-order extrapolation, although computationally expedient, is well known to fail even for some simple flows, especially when turbulent structures interact with the boundaries or if time-varying inflow conditions are imposed. The Navier–Stokes characteristic boundary condition approach provides more accurate boundary conditions, but requires the use of special discretizations at boundaries. The present paper develops a new technique based on the Navier–Stokes characteristic boundary condition approach to derive values for ghost cells that significantly improve the treatment of boundaries over simple extrapolation, but retain the ghost cell approach. Furthermore, it is demonstrated in the context of a Godunov integration procedure that the new method provides accurate results, while allowing the use of the same stencil and numerical methodology near the boundaries as in the interior.

Authors:

Motheau, Emmanuel ^[1]; Almgren, Ann ^[1]; Bell, John B. ^[1]

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+ Show Author Affiliations

1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Publication Date:

Tue Jul 25 00:00:00 EDT 2017

Research Org.:

Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1525185

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

AIAA Journal

Additional Journal Information:

Journal Volume: 55; Journal Issue: 10; Journal ID: ISSN 0001-1452

Publisher:

AIAA

Country of Publication:

United States

Language:

English

Subject:

97 MATHEMATICS AND COMPUTING