Structure Analysis of the Stabilizing Region of Plane, Laminar Fuel-Jet. Flames.

Abstract

An experimental study was made of the structure of the stabilizing region of plane, laminar fuel-jet flames of methane ejected parallel to the air stream. Velocity and temperature profiles were measured in detail and were analyzed to yield the distributions of the heat-flux vector and the heat-release rate throughout the stabilizing region. Results show that, a region of the higher heat-release rate appears near the flame base. This is due to combustion of a small volume of premixed gases produced as a result of fuel and air coming into direct contact. Another region of the negative heat-release rate appears on the fuel side of the flame zone. This is attributed to pyrolysis-type reactions. Towards the fuel-nozzle wall the heat-release rate decreases remarkably, still the heat-release rate in the dark space is substantial.

Further studies of the reaction kernel structure and stabilization of jet diffusion flames

“…Numerous studies of the structure and stability of laminar diffusion flames have been conducted in both normal earth gravity (1g) and microgravity (lg) [1][2][3][4][5][6][7][8][9][10][11][12]. Although several attempts [1][2][3] were made to reveal the internal structure of the flame-stabilizing region experimentally, most previous works were limited to overall flame characteristics. Qin et al [13] examined the local conditions of the lifted triple flame structure in a partially premixed methane jet.…”

Structure of the Stabilizing Region of a Laminar Jet Diffusion Flame

“…Robson and Wilson (1969) first attempted to study the stability of laminar methane diffusion flames by means of flame structural measurements in the base region. Kawamura and Asato (1975) and Kawamura et al (1980) followed their approach to study mainly the thermal structure by applying the structure analysis techniques, similar to those employed by Datta et al (1971) and Datta and Reed (1972) for investigating the stabilizing region of premixed flames. The previous work has contributed to better understanding of the flame structure in the base region, yet relevant interpretations of the structure data in connection with the flame stability have remained unclear mainly because the mechanism of flame holding has not been discussed in an explicit manner.…”

The anchoring of gaseous jet diffusion flames in stagnant air

“…1 (y/x) azimuthal coordinate similarity variable in the boundary layer at the wall work reviewed in the bookby Gaydon and Wolfhard [3] and the more recent work of Robson and Wilson [10], Kawamura and Asato [6], Kawamura et al [7] and, particularly, the extensive work carried out and reviewed by Takahashi and Schmoll [13] and Takahashi et al [14]. The size of the flame attachment región is very small in high Reynolds number flows of typical jet diffusion llames, and this contributes to the difficulties of the experimental description.…”