| Popis: |
Code verification is an essential process in computational analysis. The lack of access to the source code in commercial softwares often makes this process very difficult to be performed. Usually, the use of manufactured solutions is not feasible and analytical solutions of the Navier Stokes Equations are not sufficient because normally many terms of the equations are null. The situation is more troublesome for unsteady flows since it is more difficult to find analytical solutions and errors can accumulate in time. Simulations focused on turbulent fluctuations or sound wave generation associated with aeroacoustics applications are even more important and difficult to perform, because even minute errors can have a large impact on the flow. Here it is proposed a code verification method based on the simulation of a mixing layer, a canonical flow that transitions to turbulence. This flow is linearly unstable and the stability calculation affords a semi analytical solution. The paper shows how this solution can be used for classification of code performance. In the study, several commercial codes have been tested and very different code performances were obtained, both in terms of accuracy and grid requirements. |
