Flow, Mixing, and Combustion Characteristics of High Velocity Ratio Plane Coaxial and Convoluted Trailing Edge Nozzles

Abstract

AbstractThe work presents a comparative study of the fuel-air mixing and flame stabilization characteristics of two, high velocity ratio, coaxial jet configurations comprising either a plain circular arrangement or a convoluted trailing edge nozzle. The high velocity ratio, coaxial stream interaction results in a stable central recirculation zone at a distance downstream of the nozzle exit where a range of flame configurations can be successfully stabilized under suitable flow and mixing conditions. In this configuration, the reacting front region is supplied with both a radial and an axial propane-air mixture gradient which are formulated through a central upstream premixer duct and the coannular jet interaction downstream of the exit plane. Depending on the nozzle shape, plain circular or convoluted, a variety of partially premixed turbulent flame configurations can be obtained at a position detached farther from the nozzle exit. Measurements of mixture concentrations, mean temperatures, and flame chemi...