Optimal Strategy for Modelling Turbulent Flows with Ensemble Averaging on High Performance Computing Systems

Abstract

The high-fidelity modelling of turbulent flows is one of the actual problems, actively performed on high performance computing systems. The main issue for these simulations is related to the need of long time averaging to obtain reliable statistics of interest for scientists and engineers. The two recent publications deal with the problem of long time integration, suggesting an ensemble averaging approach, which allows to replace the single long time integration with multiple simulations of much shorter time intervals. These papers provide two different simulation scenarios to perform the simulations. The current paper proposes the generalized approach combining them all together. The paper provides the criterion to choose the optimal scenario, minimizing the overall simulation time for a given number of computational resources. The proposed generalization substantially extends the range of applicability for the suggested ensemble averaging methodology. The validation results considered in the paper demonstrate additional 20% simulation speedup for the generalized approach compared to the basic ones proposed earlier.