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Computation of confined coflow jets with three turbulence models
Author(s) -
Zhu J.,
Shih T.H.
Publication year - 1994
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/fld.1650191005
Subject(s) - reynolds stress , turbulence , reynolds stress equation model , k epsilon turbulence model , mechanics , computation , turbulence modeling , mathematics , flow (mathematics) , computational fluid dynamics , finite volume method , physics , k omega turbulence model , algorithm
A numerical study of confined jets in a cylindrical duct is carried out to examine the performance of two recently proposed turbulence models: an RNG‐based K ‐ϵ model and a realizable Reynolds stress algebraic equation model. The former is of the same form as the standard K ‐ϵ model but has different model coefficients. The latter uses an explicit quadratic stress‐strain relationship to model the turbulent stresses and is capable of ensuring the positivity of each turbulent normal stress. The flow considered involves recirculation with unfixed separation and reatachment points and severe adverse pressure gradients, thereby providing a valuable test of the predictive capability of the models for complex flows. Calculations are performed with a finite volume procedure. Numerical credibility of the solutions is ensured by using second‐order‐accurate differencing schemes and sufficiently fine grids. Calculations with the standard K ‐ϵ model are also made for comparison. Detailed comparisons with experiments show that the realizable Reynolds stress algebraic equation model consistently works better than does the standard K ‐ϵ model in capturing the essential flow features, while the RNG‐based K ‐ϵ model does not seem to give improvements over the standard K ‐ϵ model under the flow conditions considered.