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, equal-mass 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 fluid-mixing frequency for a practical range of fuel-air 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;
- Fuel-Air Ratio;
- Mixing;
- Rayleigh Scattering;
- Reaction Kinetics;
- Turbulence;
- Fluid Mechanics;
- Independent Variables;
- Mathematical Models;
- Mixing;
- Fluid Mechanics and Heat Transfer