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Title: Implicit-explicit Godunov schemes for unsteady gas dynamics

Abstract

Hybrid implicit-explicit schemes are developed for Eulerian hydrodynamics in one and two space dimensions. The hybridization is a continuous switch and operates on each characteristic field separately. The explicit scheme is a version of the second order Godunov scheme; the implicit method is only first order accurate in time but leads to second order accurate steady states. This methodology is developed for linear advection, nonlinear scalar problems, hyperbolic constant co-efficient systems, and for gas dynamics. Truncation error and stability analyses are done for the linear cases. This implicit-explicit strategy is intended for problems with spatially or temporally localized stiffness in wave speeds. By stiffness we mean that the high speed modes contain very little energy, yet they determine the explicit time step through the CFL condition. For hydrodynamics, the main examples are nearly incompressible flow, flows with embedded boundary layers, and magnetohydrodynamics; the latter two examples are not treated here. Several numerical results are presented to demonstrate this method. These include, stable numerical shocks at very high CFL numbers, one-dimensional flow in a duct, and low Mach number shear layers.

Authors:
Publication Date:
Research Org.:
Maryland Univ., College Park, MD (United States)
OSTI Identifier:
121352
Resource Type:
Miscellaneous
Resource Relation:
Other Information: TH: Thesis (Ph.D.); PBD: 1992
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; 99 MATHEMATICS, COMPUTERS, INFORMATION SCIENCE, MANAGEMENT, LAW, MISCELLANEOUS; 66 PHYSICS; INCOMPRESSIBLE FLOW; NUMERICAL SOLUTION; HYDRODYNAMICS; ONE-DIMENSIONAL CALCULATIONS; MACH NUMBER; SHOCK WAVES

Citation Formats

Collins, J P. Implicit-explicit Godunov schemes for unsteady gas dynamics. United States: N. p., 1992. Web.
Collins, J P. Implicit-explicit Godunov schemes for unsteady gas dynamics. United States.
Collins, J P. 1992. "Implicit-explicit Godunov schemes for unsteady gas dynamics". United States.
@article{osti_121352,
title = {Implicit-explicit Godunov schemes for unsteady gas dynamics},
author = {Collins, J P},
abstractNote = {Hybrid implicit-explicit schemes are developed for Eulerian hydrodynamics in one and two space dimensions. The hybridization is a continuous switch and operates on each characteristic field separately. The explicit scheme is a version of the second order Godunov scheme; the implicit method is only first order accurate in time but leads to second order accurate steady states. This methodology is developed for linear advection, nonlinear scalar problems, hyperbolic constant co-efficient systems, and for gas dynamics. Truncation error and stability analyses are done for the linear cases. This implicit-explicit strategy is intended for problems with spatially or temporally localized stiffness in wave speeds. By stiffness we mean that the high speed modes contain very little energy, yet they determine the explicit time step through the CFL condition. For hydrodynamics, the main examples are nearly incompressible flow, flows with embedded boundary layers, and magnetohydrodynamics; the latter two examples are not treated here. Several numerical results are presented to demonstrate this method. These include, stable numerical shocks at very high CFL numbers, one-dimensional flow in a duct, and low Mach number shear layers.},
doi = {},
url = {https://www.osti.gov/biblio/121352}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Dec 31 00:00:00 EST 1992},
month = {Thu Dec 31 00:00:00 EST 1992}
}

Miscellaneous:
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