Physical and Chemical Processes in Flames
Abstract
The objective of the present program was to study the structure and response of laminar premixed and nonpremixed flames with emphases on effects of high pressure, flame/flow unsteadiness, and chemistry. Studies on flame dynamics show strong coupling between the intrinsic flamefront hydrodynamic cellular instabilities and the diffusional/thermal cellular or pulsating instabilities, for mixture Lewis numbers that are respectively smaller or larger than unity. Linear and nonlinear stability analyses on diffusion flames show regimes of stability and the influence of heat loss on their boundaries. Studies on combustion chemistry led to the determination of laminar flame speeds of high fidelity at atmospheric and high pressures for CO/H2 as well as C2-C3 mixtures with air, and the counterflow ignition temperatures of dimethyl ether (DME) and 1,3-butadiene, allowing developments of detailed and reduced reaction mechanisms. A mathematical theory and computational algorithm termed directed relation graph was developed and then further improved that allows systematic and rapid determination and thereby elimination of unimportant species and reactions of detailed mechanisms, leading to skeletal mechanisms that are sufficiently small either for computational simulation of complex combustion phenomena. These results are expected to be useful to the general interests of AFOSR in the fundamental and practical issues of flame dynamics and chemical kinetics, turbulent combustion, soot formation, radiative heat transfer, flame extinction, stabilization, flammability, and supersonic combustion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2007
- Accession Number
- ADA472032
Entities
People
- Chung K. Law
Organizations
- Princeton University