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Simulation of round jets with nozzle‐dependent inflow conditions using the k −ε turbulence model
Author(s) -
Reinhardt Yvonne,
Kleiser Leonhard
Publication year - 2014
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.201410310
Subject(s) - nozzle , reynolds averaged navier–stokes equations , turbulence , mechanics , jet (fluid) , reynolds number , inflow , discharge coefficient , physics , flow (mathematics) , thermodynamics , materials science
Abstract In view of the “round jet initial condition anomaly”, discussed in literature, we investigate the effect of inflow conditions resulting from the use of different nozzle geometries to form the jet. RANS simulations in the framework of OpenFOAM using the k − ε turbulence model are performed. As the standard model coefficient C ε1 = 1.44 is known to overpredict spreading rates for round jets, a value of C ε1 = 1.6 was recommended for this case already in the 1970's. While this works well for jets issuing from long pipes, it does not give satisfactory results for other nozzle geometries. To overcome this deficiency while keeping the k − ε model, we suggest modified coefficients C ε1 based on profiles of mean flow and turbulence at the nozzle exit. We determine optimal values of C ε1 for three different nozzle geometries, and test them at various Reynolds numbers. Good agreement with experimental data is obtained. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)