- Author
-
Yakhot, V.
|
Thangam, S.
|
Gatski, T. B.
|
Orszag, S. A.
|
Speziale, C. G.
- Title
- Development of Turbulence Models for Shear Flows by a Double Expansion Technique. Contractor Report.
- Coporate
- National Aeronautics and Space Administration, Langley Research Center, Hampton, VA
- Sponsor
- National Aeronautics and Space Administration, Langley Research Center, Hampton, VA
- Report
-
NASA CR-187611; ICASE Report 91-65; Work Unit No. 505-90-52-01,
July 1991,
26 p.
- Distribution
- Available from National Technical Information Service
- Contract
- NASA-CONTRACT-NAS1-18605
- Keywords
-
turbulence
|
expansion
- Identifiers
- renormalization groug (RNG); scale expansions; Reynolds stress; dissipation terms; time scale
- Abstract
- Turbulence models are developed by supplementing the renormalization group (RNG) approach of Yakhot and Orszag with scale expansions for the Reynolds stress and production of dissipation terms. The additional expansion parameter is the ratio of the tubulent to mean strain time scale. While low-order expansions appear to provide an adequate descritpion for the Reynolds stress, no finite truncation of the expansion for the production of dissipation term in powers of eta suffices--terms of all orders must be retained. Based on these ideas, a new two-equation model and Reynolds stress transport model are developed for turbulent shear flows. The models are tested for homogeneous shear flow and flow over a backward facing step. Comparisons between the model predictions and experimental data are excellent.