PDF Modeling of Turbulent Combustion
Abstract
The overall objective of the research was to advance and extend methodologies for the modeling and simulation of turbulent combustion. Probability density function (PDF) calculations were performed of piloted jet turbulent non-premixed flames to demonstrate the ability of the approach to represent local extinction and re-ignition and to characterize the performance of different sub-models. PDF calculations were performed of lifted flames in vitiated co-flows, and the results were analyzed to show that the stabilization mechanism is auto-ignition. Timeaveraging strategies were shown to be very effective in reducing bias in the Monte Carlo methods used to solve the PDF equations. Strategies were developed for implementing combustion chemistry on parallel computers, resulting in speed-ups of up to a factor of five (relative to the straightforward purely-local strategy). The method was shown to scale up to 4096 cores. Algorithms and codes were developed to implement the combined methodology of large-eddy simulation (LES) and filtered density function (FDF). Second-order schemes were developed and demonstrated for particle tracking, which (in contrast to standard methods) also accurately represent the evolution of the particle number density, and second-order accurate splitting schemes were developed for the stochastic differential equations that arise in LES/FDF.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 2008
- Accession Number
- ADA498304
Entities
People
- Stephen B. Pope
Organizations
- Sibley School of Mechanical and Aerospace Engineering