Fractal behavior of a wrinkled annular diffusion flame--

Journal Article · Mon Jan 01 00:00:00 EST 1990 · Combustion and Flame; (USA)

DOI:https://doi.org/10.1016/0010-2180(90)90085-6· OSTI ID:7170182

Gutmark, E; Hanson-Parr, D M; Parr, T P; Schadow, K C ^[1]

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1. Naval Weapons Center, China Lake, CA (USA). Research Dept.

Fractal geometry is used to describe quantitatively the random character of a turbulent wrinkled diffusion flame. The article describes how basic ideas of mathematics of fractals can be applied to study the changes in the irregularity of the flame's surface at various axial positions. In the present work, the planar laser-induced-fluorescence (PLIF) imaging technique has been used to map the hydroxyl concentration in an annular diffusion flame with propane fuel. The short pulse duration (18 ns) of the laser sheet enabled instantaneous pictures of the flame structure to be obtained with high spatial resolution of 0.5 {times} 0.5 {times} 0.5 mm. The isopleths of concentration were highly wrinkled and random in character, both in space and time. They were measured in flames that were forced at different instability frequencies, in order to stabilize the roll-up of the vortices in the flame shear layer and to simulate vortex merging. Measurements were done from the flameholder to the flame's end at many axial positions, in order to study the evolution of the flame structure. The fractal dimension was calculated for all these conditions, using two methods: the Kolmogorov-Hansdorff definition and the perimeter area relation.

• OSTI ID: 7170182
• Journal Information: Combustion and Flame; (USA), Vol. 70:1; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
42 ENGINEERING
FLAMES
DIFFUSION
CALCULATION METHODS
CHEMICAL REACTION KINETICS
FLUORESCENCE SPECTROSCOPY
GEOMETRY
HYDROXYL RADICALS
TURBULENT FLOW
EMISSION SPECTROSCOPY
FLUID FLOW
KINETICS
MATHEMATICS
RADICALS
REACTION KINETICS
SPECTROSCOPY
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry
420400 - Engineering- Heat Transfer & Fluid Flow
400101 - Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures