Investigation of the Structure of a Reacting Hydrocarbon-Air Planar Mixing Layer
Abstract
Mixing-controlled combustion of a hydrocarbon-air system was investigated experimentally in a planar two-stream mixing layer using planar laser-induced fluorescence of OH for visualization of the reaction zone, and planar LII of soot, which was found to effectively mark the edge of the parent fuel entrainment. The high-temperature combustion was found to locate on the lean reactant (air) side of the mixing layer, and was minimally perturbed by the fluid motion, resulting in the formation of an internal' mixing layer, reminiscent of a non-reacting mixing layer, between the combustion products and the neat fuel stream. For the same inlet hydrodynamic conditions, the large-scale structure spacing was found to decrease when the high-speed stream contained the fuel, whereas air as the high-speed fluid resulted in a lengthening of the structure spacing compared to non-reacting conditions. The effective density ratio established by the high temperature reaction zone located on the air side of the mixing layer is believed to be the cause for this behavior. A tripped high-speed boundary layer was found to have a large effect on non-reacting passive scalar measurements, but was not found to affect the mixing layer structure under reacting conditions, suggesting the that the heat release serves to make the Kelvin-Helmholtz instability dominant.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 19, 2001
- Accession Number
- ADP012106
Entities
People
- Corradini
- Farrell
- Foster
- Ghandhi
- Reitz
Organizations
- University of Wisconsin–Madison