MULTILEVEL SOLUTION-ADAPTIVE DIFFERENCING STRATEGIES FOR CONVECTIVE FLOWS

Abstract

A solution-adaptive differencing that embodies the concept of multilevel calculations on grid subsets is presented, and the performance of different strategies for coupling the calculations on the multiple grid levels is evaluated for selected test problems. The solution-adaptive differencing scheme equidistributes a measure of the solution error in the domain. The first step in the algorithm is to compute an error estimate based on a preliminary first-order upwind solution. Grid points with error estimates higher than a prespecified value are flagged, and in these flagged regions, a third-order-accurate solution is obtained. A multiple-grid-type calculation is then performed, to the desired level of accuracy, between the outer unflagged region and the inner flagged regions. Three different strategies for the multiple-grid calculations are examined here. For each strategy the improvements in the solution accuracy and the associated computational effort are presented for two test problems.

Notes

Address correspondence to Prof. Sumanta Acharya, Mechanical Engineering Department, Louisiana State University, Room 2513A CEBA, Baton Rouge, LA 70803-6413, USA.