Multiscale Turbulent Reacting Flows and Data-Based Modeling

North Carolina State University, Raleigh NC

Investigators

Abstract

This research project investigates a multiscale flame-embedding approach for the computation of turbulent flames. The model is based on the coupling of large-eddy simulation (LES) for the description of the flow and for flame tracking and embedded 1D stochastic solutions of flamelets based on the one-dimensional turbulence (ODT) model. Important features of the framework include the upscaling of ODT solution to the LES, the downscaling of LES solutions to ODT, and capturing of the flame front. The Lagrangian LES-ODT formulation requires the tracking, spawning, and removal of ODT solutions as they are advected along the flame. The formulation also requires a robust formulation for the filtering of the density from the fine-grained solution of ODT to the LES along with the filtering of transport and source terms for scalars used to track the flame in LES. Wavelet-based methods will be investigated to establish consistency between the LES and ODT velocity fields and their transport. An optimal parameterization of the thermo-chemical scalars using principal component analysis will be used to improve computational efficiency. This research addresses the prediction of physical processes occurring in the production of energy through combustion. The work aims to develop next-generation modeling tools that can potentially reduce the turn-around time for the design of combustion systems through simulation and to investigate mechanisms to improve combustion efficiency and reduce pollutants.