An open 3D CFD model for the investigation of flow environments experienced by freshwater fish
Ali Hassan Khan, Karla Ruiz Hussmann, Dennis Powalla, Stefan Hoerner, Maarja Kruusmaa, Jeffrey A. Tuhtan
Abstract
Computational fluid dynamics (CFD) provides a powerful numerical tool to simulate and study many of the complex fluid-body interactions experienced by freshwater fish. However, major gaps remain in the application of CFD to study the fluid-body interactions of fish, including the absence of an openly available reference body geometry, the lack of a detailed study on suitable numerical methods and a deficit of available velocity laboratory measurements for model calibration and validation. To address these gaps, we provide a set of numerical models based on the open-source CFD toolkit OpenFOAM. The contributions of this work are two-fold: First, to provide a validated openly available numerical setup using a realistic fish model geometry including laboratory velocity measurements. Second, to determine the best-performing turbulence models and near-wall treatments using Reynolds-Averaged Navier-Stokes (RANS) numerical simulations. Finally, we conclude with a critical evaluation of the effects and trade-offs of resolving or modelling the boundary layer (BL) in numerical studies of fish-shaped bodies.