exaFOAM Industrial Benchmark B2 - Unsteady primal and adjoint solution around the TME CHR car

This benchmark represents an industrial application of the unsteady optimization infrastructure of OpenFOAM, using the Toyota CHR car geometry. When used with unsteady flows, the adjoint equations are integrated backwards in time, requiring the instantaneous flow fields to be available at each time-step of the adjoint solver, which noticeably increases storage requirements in large-scale problems.

To avoid extreme treatments, such as the full storage of the computed flow fields or their recomputations from scratch during the solution of the adjoint equations and to reduce the re-evaluation overhead incurred by the widely used check-pointing technique, lossy compression techniques were implemented into the adjointOptimisation library of OpenFOAM, during the exaFOAM project. The re-computation cost is reduced by efficiently compressing the entire compressed flow series and storing it in memory.