Surrogate models for multiregime flow problems

Abstract

Surrogate modeling methods based on polynomial chaos expansion (PCE) and bifidelity (BF) approaches are investigated in the context of two-dimensional flow past two square cylinders. The overall wake behavior of this flow has been shown by Ma et al. [Phys. Fluids 29, 033604 (2017)1070-663110.1063/1.4979134] to give rise to multiple flow regimes with various vortex shedding patterns depending on the cylinder gap spacing, g∗, and oncoming flow Reynolds number, Re. Within the scope of surrogate modeling, the possibility of multiple flow regimes occurring with varying input parameters forms an intriguing challenge, hence, the attempt in the present work to construct a model that will accurately ..