Physical and Chemical Processes in Flames
Abstract
The objectives of the program were two fold, namely (1) to identify the controlling chemistry of aeropropulsion fuels and develop detailed and reduced mechanisms describing their oxidative reaction pathways and rates, and (2) to understand and quantify the unstable modes of combustion and their influence on flame extinction. Concerning Objective 1, laminar burning velocities of C1 to Cg alkanes with air, and blends of butane, ethylene and benzene with air, were experimentally measured. These results were used, together with other chemical kinetic information towards the development of a comprehensive C3-mechanism. A mathematical theory based on computational singular perturbation was formulated, allowing for the systematic reduction of detailed reaction mechanism to simpler ones without loss of the comprehensiveness of the kinetic description. Concerning Objective 2, the steady and pulsating propagation of flames were analytically and computationally studied, at atmospheric and elevated pressures. Results showed that the onset of pulsation facilitates flame extinction, that positive and negative stretch respectively promote and retard its onset, that radiative loss promotes flame front instability and extinction, and that there is strong coupling between flame front stability and the intrinsic chemical chain mechanisms. 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, radiative hear transfer, flame extinction, stabilization, flanun.ability, and supersonic combustion.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2001
- Accession Number
- ADA396319
Entities
People
- Chung K. Law
Organizations
- Princeton University