Verification Of Unstructured Grid Adaptation Components

Unstructured grid techniques have the potential of minimizing discretization errors for production analysis workflows where the control of errors is critical to obtaining reliable simulation results. Recent progress has matured a number of independent implementations of flow solvers, error estimation methods, and anisotropic grid adaptation mechanics. Here, the interoperability of several separately developed unstructured grid adaptation tools is verified using analytic functions and the Code Comparison Principle. Three analytic functions with different smoothness properties are adapted to show the impact of smoothness on implementation differences. A scalar advection-diffusion problem with an analytic solution that models a boundary layer is adapted to test individual grid adaptation components. While optimal asymptotic error convergence rates are achieved with many grid adaptation tool combinations for the scalar problems, the scalar problems also illustrate known differences in grid adaptation component implementations and a previously unknown interaction between components. Laminar flow over a delta wing is verified with multiple, independent grid adaptation procedures to show consistent convergence to fine-grid forces and pitching moment. These verification efforts form the nucleus of a benchmark to verify the integration of unstructured grad adaptation components and support production analysis workflows.