Subgrid-scale model for the scalar dissipation rate in nonpremixed combustion
- LLNL
A subgrid-scale model is presented for the scalar dissipation rate in nonpremixed turbulent reacting flows. Inputs to the model are the filtered density, the Favre- filtered temperature and the Favre-filtered misture-fraction. The model contains a coefficient which is determined by assuming a form for the scalar energy spectrum. Inputs to the presumed spectrum are the integral and dissipation length scales of the scalar field. These quantities are estimated locally from the Favre-filtered velocity field, resulting in a model coefficient which is spatially and temporally dependent. The model is tested a priori using data from a Direct Numerical Simulation (DXS) of a temporal reacting mixing layer. Estimated values of the dissipation rate are found in good agreement with dissipation rates computed directly from the DXS data. Furthermore, the presumed spectrum methodology is found to accurately predict the mean value of the model coefficient as well as its spatial and temporal variations.
- Research Organization:
- Lawrence Livermore National Laboratory, Livermore, CA
- Sponsoring Organization:
- USDOE Office of Defense Programs (DP)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 2898
- Report Number(s):
- UCRL-JC-131727; DP0101031; ON: DE00002898
- Country of Publication:
- United States
- Language:
- English
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