Experimental determination of the mixing frequency parameter for coalescence/dispersion modeling of turbulent combustion
Abstract
The basic time scales of turbulent mixing in a high intensity combustion environment were determined. The results of this research are directly applicable to the coalescence/dispersion (C/D) modeling technique of modeling turbulent combustion. The combustion field is divided into isolated, equalmass elements which, while continuously undergoing batch chemical reaction, interact at a specified frequency, (BETA). The hypothesis is that (BETA) is related to the physics of the modeled system and, can be characterized by a single, slowest mixing time scale. The specific objectives are: (1) measurement of the characteristic fluidmixing frequency for a practical range of fuelair equivalence ratios; (2) comparison of the experimental data with existing analytical and numerical models for combustor mixing frequencies which are derived from global fluid mechanical arguments; and (3) interpretation of the measurements of the mixing frequency, (BETA), to model its dependence on the physical parameters of the combustion process. Three parallel tasks were focused on: development of the Rayleigh scattering diagnostic system, and the tracer gas injection and measurement technique; the vectorization of appropriate statistical algorithms for data reduction and analysis; and, study of the C/D theoretical basis and application of numerical simulation of previous experiments.
 Publication:

Annual Progress Report Washington Univ
 Pub Date:
 September 1984
 Bibcode:
 1984wus..rept.....B
 Keywords:

 Combustion;
 Frequencies;
 FuelAir Ratio;
 Mixing;
 Rayleigh Scattering;
 Reaction Kinetics;
 Turbulence;
 Fluid Mechanics;
 Independent Variables;
 Mathematical Models;
 Mixing;
 Fluid Mechanics and Heat Transfer