Unified RANS-LES Simulations of Turbulent Swirling Jets and Channel Flows
The accurate and efficient simulation of both attached and separated flows represents a huge challenge. RANS methods suffer from the lack of ability to simulate instantaneous turbulence structures, and LES methods are computationally very expensive regarding the simulation of wall-bounded flows, which have to be considered very often. A promising alternative is the use of hybrid RANS-LES methods, but existing hybrid methods like DES face many questions. The paper focuses on the use of unified RANS-LES methods implied by stochastic analysis as an alternative to using existing hybrid RANS-LES methods. The theoretical basis of the approach applied and applications to turbulent channel flows and turbulent swirling jet flows will be presented. The accuracy and cost features of the unified RANS-LES model will be discussed in comparison with other (in particular DES) hybrid methods.
KeywordsLarge Eddy Simulation Vortex Breakdown Turbulent Channel Flow Detach Eddy Simulation Swirl Number
This work was partially sponsored by the Air Force Office of Scientific Research, USAF, under grant number FA9550-05-1-0485 monitored by Dr. John Schmisseur. We would also like to acknowledge support through NASA’s NRA research opportunities in aeronautics program (Grant No. NNX12AJ71A) with Dr. P. Balakumar as the technical officer. The computational resources have been provided by the UW Institute for Scientific Computation.
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