Adaptive grid techniques for elliptic fluidflow problems
Abstract
The adaptive grid techniques are described for elliptic fluid flow problems. The method is an extension of a local refinement technique developed by Berger for systems of hyperbolic equations. Local refined grids are overlaid on a coarser base grid. Recursive use of this technique allows an arbitrary degree of grid refinement. Two classes of elliptic flows are identified; they are characterized as having strong or weak viscous inviscid interactions. Adaptive solution strategies, active and passive, respectively, are developed for each class. The simpler method is used to solve the steady, laminar, incompressible Navier Stokes equations. Central differencing of the convective terms is implemented with the defectcorrection method to stabilize the solution method for all cell Reynolds numbers. Uniform grid calculations are performed for the laminar backstep flow. Richardson estimated solution and truncation errors are compared to accurate estimates of the same quantities for the backstep flow. The solution error is well predicted. The truncation error estimates are less accurate, but they reliably indicate where grid refinement is required. Active adaptive calculations of the backstep are made, using boundary aligned refinement.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 December 1985
 Bibcode:
 1985STIN...8712814C
 Keywords:

 Computational Fluid Dynamics;
 Computational Grids;
 Convective Flow;
 Data Reduction;
 Ellipses;
 Finite Element Method;
 Fluid Flow;
 Mechanical Properties;
 NavierStokes Equation;
 Recursive Functions;
 Error Analysis;
 Flow Equations;
 Hyperbolas;
 Inviscid Flow;
 Reynolds Number;
 Truncation Errors;
 Viscous Flow;
 Fluid Mechanics and Heat Transfer