Large-Scale Vortex Generation Modeling

Abstract

Methods of modeling vortex generation in computational fluid dynamics calculations without meshing the vortex generating device are investigated. In this way, the effect of adding vortices to existing flows can be assessed without the need to modify the computational grid; this can represent a significant saving. Previous work in this area has focused on boundary layer control. This study looks at larger scale applications, such as using vortices for force augmentation or directing flow. Two different approaches are used: modeling the vortex generator and modeling just the vortex alone. For the former, an existing method, which acts to align the flow with the vortex generator by adding a forcing term to the governing equations, is tested, but found to be unsuitable for use on this scale. The other approach is to add specified vortex velocity profiles, allowing the introduction of arbitrary vortices. A new version is developed to add continuous 3D velocity distributions in regions where desired vortices are to be created. It is implemented using several different forms of forcing. After basic testing, all methods are applied in a practical engineering case using a commercial solver.