An improved passive vortex generator model for flow separation control
2010 (English)In: 5th Flow Control Conference, 2010, 2010-5091- p.Conference paper (Refereed)
Modeling arrays of passive vortex generators (VGs) pairs located in the fully turbulent boundary layer of a two-dimensional flat plate, generating streamwise counterrotating vortex structures is investigated. Usually, a sound computational fluid dynamics investigation requires an adequate grid with a corresponding large number of grid points around such VGs in order to obtain an accurate solution. This leads to a time-demanding grid generation which often comes along with lots of challenges during the creation. An effective way to get around this time-consuming process is to introduce a way to model these flow separation devices statistically and, by that, to add their statistical physical effects to the governing equations rather than resolving their geometries in the computational grid. Here, a computational tool for statistical VG modeling is presented that makes it possible to simulate and model passive VGs in wall-bounded flows, whereas the need for a local mesh refinement is no longer required. Previous research results of the presented statistical modeling of passive VGs have shown that it is necessary to improve the original statistical VG model in terms of the vortex stress modeling in order to evaluate results not only qualitatively, but also quantitatively. Computational results for spanwise averaged fully resolved three-dimensional VGs, experimental results, as well as two-dimensional original VG model results are evaluated and compared to two improved statistical VG model approaches that are presented here. It is shown that the improved VG models gives better results than the original VG model in terms of the nearfield vortex stresses that are important for the immediate respons of the boundary layer flow on momentum mixing. The impact of the improved VG models on flow separation control could be proven to be stronger and thus, closer to experiments and fully resolved results.
Place, publisher, year, edition, pages
2010. 2010-5091- p.
Computational grids, Computational results, Computational tools, Counter-rotating vortices, Flat plate, Flow separation control, Governing equations, Grid generation, Local mesh refinement, Model approach, Model results, Near-field, Number of Grids, On flow, Physical effects, Research results, Separation devices, Statistical modeling, Time-consuming process, Turbulent boundary layers, Vortex generators, Vortex stress, Wall bounded flows
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-149690ScopusID: 2-s2.0-78649514711ISBN: 978-160086745-3OAI: oai:DiVA.org:kth-149690DiVA: diva2:741797
5th Flow Control Conference, 28 June 2010 through 1 July 2010, Chicago, IL, United States
QC 201408292014-08-292014-08-262014-08-29Bibliographically approved