Spectral characteristics of the aerodynamic field of a turbulent diffusion flame at a low Froude number
Abstract
Turbulent diffusion flames, like those found in a propulsive system, are examined in the case of a low Froude number (no more than 1/100,000). The gaseous products initially have a low velocity, with an inertia which is weak compared to that of gravity. Experimental results are presented from trials run with a specially designed burner emitting fine refractory particles, i.e., propane gas laced with zirconium dioxide particles averaging 2 microns across. Laser anemometry was employed for counting the particles, in conjunction with a computer. Vertical profiles were developed of the flame, covering the velocity fluctuations and their frequency, and with three different energy inputs (15.8, 23, and 38 kW) into the flame. A characteristic low frequency peak was observed, as well as a transition zone to the turbulence. The fuel burning was confined to periodic or quasi-periodic regions of the flow. Turbulence is concluded to be confined to the final combustion phase in flames with a low Froude number.
- Publication:
-
Academie des Sciences Paris Comptes Rendus Serie Sciences Mathematiques
- Pub Date:
- September 1982
- Bibcode:
- 1982CRASM.295..309G
- Keywords:
-
- Combustible Flow;
- Diffusion Flames;
- Flame Spectroscopy;
- Turbulent Diffusion;
- Buoyancy;
- Carbon Monoxide;
- Froude Number;
- Laser Doppler Velocimeters;
- Spectrum Analysis;
- Fluid Mechanics and Heat Transfer