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U.S. Department of Energy
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Iterative solutions to Navier-Stokes difference equations

Thesis/Dissertation ·
OSTI ID:5666725

The time-dependent two-dimensional Navier-Stokes equations are used to model the evolution of the flow of a Newtonian fluid. Implicit finite-difference equations on a MAC discretization grid are used to approximate the continuity, enthalpy and momentum equations. By time-lagging the pressure and velocity variables in the enthalpy equation, the discrete enthalpy equations are uncoupled from the continuity and momentum equations and solved separately. The coupled system of discrete momentum and continuity equations is then transformed into the dual variable system, which is one-third of the size of the coupled system. The dual variable system is shown to be solvable for all problems unless the time step chosen is one of a finite number of values. New conditions which guarantee the solvability of the system for all positive real values of the time step are presented. Special iterative methods for solving the dual variable system are developed. A computer code, DUALIT, which solves the time-dependent two-dimensional Navier-Stokes problem, is described.

Research Organization:
Pittsburgh Univ., PA (USA)
OSTI ID:
5666725
Country of Publication:
United States
Language:
English