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NOVEL MILES COMPUTATIONS FOR JET FLOWS WITH NOISE

Paul G. Tucker
Fluid Dynamics Research Centre, School of Engineering, The University of Warwick, Coventry; Whittle laboratory, University of Cambridge, UK

Resumo

The influence of swirl on jet flow structure and noise is explored. A novel DES (Detached Eddy Simulation) type procedure is tested for a jet with co-flow case. The approach uses a k-l near wall RANS (Reynolds Averaged Navier-Stokes) model. Away from walls MILES (Monotone-Integrated Large Eddy Simulation) is used. Blending of the RANS and MILES regions is achieved using a Hamilton-Jacobi type equation. The MILES solution content enables correct turbulence evolution on relatively coarse grids. The new DESIMILES (DESmiles) approach is validated for a plane channel flow. A good law of the wall is gained. For swirling flows, far-field noise levels are calculated using the surface integral of Ffowcs Williams and Hawkings. Despite MILES use with mostly 4th order centered differencing, turbulence decays excessively downstream. Streamwise vorticity introduced by swirl (unlike with chevrons) increases noise. Lower swirl levels might bring more success. DESmiles appears promising. However, for the jet with co-flow case (due to the low co-flow Reynolds number) it is perhaps only mildly tested.