The authors discuss in detail the various heat transportation mechanisms existing in turbulent diffusion flames by use of spectral analyses. Space and time-resolved structures of turbulent diffusion flames were analyzed by two-point laser Rayleigh spectroscopy (LRS) which did not directly interfere with the combustion media during measurement. The turbulent diffusion flame structures were divided into 4 regions based on the characteristics of their spectral analysis of time-dependent temperature signals. In order to discuss the macroscopic heat transportation mechanism, the coherent function from cross and power spectral functions at Region I∼IV was analyzed. From these analyses, the following diffusion characteristics at each region were revealed. Region I : three-dimensional diffusion mechanism (x-, r-, z-axes), Region II : one-dimensional diffusion mechanism (z-axis), Region III : two-dimensional diffusion mechanism (x-, z-axes), Region IV : no specific diffusion mechanism.
JSME international journal. Ser. 1, Solid mechanics, strength of materials
JSME international journal. Ser. A, Mechanics and material engineering
JSME international journal. Ser. 3, Vibration, control engineering, engineering for industry
JSME international journal. Ser. C, Dynamics, control, robotics, design and manufacturing
JSME International Journal Series A Solid Mechanics and Material Engineering
JSME International Journal Series C Mechanical Systems, Machine Elements and Manufacturing