Performance of Subgrid Flamelet Model in LES of Reacting, Turbulent Flows
Abstract
Large eddy simulation (LES) with a flamelet-based chemistry model has been evaluated through a priori and a posteriori tests in both decaying homogeneous turbulence and spatially developing mixing layers. The present fiamelet-LES approach involves a series of models, among which are the models for the PDF of mixture-fraction (f(z)) and the conditional filtered dissipation rate (Chi(st)). We test three models for f(z): a) delta-PDF (f(z) = delta(z)) b) beta-PDF, c) Gaussian PDF; and two models for Chi(st). The Gaussian PDF model consistently performs almost as well as the beta-PDF, and may provide an alternative approach to the beta-PDF method. This point is important to the LES simulations since the calculation of Gaussian function is much cheaper than that of beta-function. Eurthermore, it may be said from the error analyses that the counterflow model for Chi(st) has average performance in its present form and that a phenomenological model in the form of Eq. (6) exists with an optimum value of a parameter C3 to produce a better result. The a posteriori analysis shows a satisfactory performance of the fiamelet model within the context presented in this paper.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2001
- Accession Number
- ADP013646
Entities
People
- Foluso Ladeinde
- Xiaodan Cai