The Influence of Stoichiometry and Flame-Holder Shape on Flame Dynamics and Acoustics (Preprint)
Abstract
Combustion instability manifests itself by the coupling of heat release and chamber acoustics. These instabilities can be present in any type of combustion system, including gas turbine engines, scramjet engines, and industrial furnaces and boilers. Much research has been conducted on the coupling of acoustics and heat release for lean-burning systems. Historically, models of these systems assume the flames to be short and the mean fields to be incompressible. Proposed here is a new approach to coupling dynamics. If the governing equations are considered to be compressible, then a relationship among acoustics, vorticity, and pressure can be derived. In this study the relationship among vortex shedding, flame dynamics, and acoustics is explored for a bluff-body-stabilized flame using high-speed flame images and high-speed pressure transducers. It is demonstrated that the flame radiates sound over a broad spectrum and that thermoacoustic coupling occurs when the flame sound radiation couples with one of the modes of the combustion chamber.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2012
- Accession Number
- ADA560400
Entities
People
- Amy Lynch
- Barry V. Kiel
- Beth Huelskamp
- Nick Parr
- Reza Kashani
- Stanislav Kostka
Organizations
- Air Force Research Laboratory