Particle Cloud Dispersion and Suspension under Reduced Gravity Conditions

Particle Cloud Dispersion and Suspension under Reduced Gravity Conditions

North Carolina A&T State University

Combustion of particle-laden systems (for example in a pulverized-coal burner) is a very difficult phenomenon to analyze. The study of this topic involves numerous variables and physical phenomena that interact and are interdependent. For example, chemical reaction and transport phenomena (e.g. heat and mass transfer) take place between the solid-gas and solid-solid phases during ignition and flame propagation in coal flames. These factors make both experiments and computational modeling of combustion of particle clouds extremely difficult. For this reason it is beneficial to create a test environment which limits the test variables, hence making analysis practicable. One such way of reducing the number of variables is to remove gravitational settling and buoyancy forces from the test environment. When these factors are removed, the complex three-dimensional problem is neatly reduced to a one-dimensional problem, thus greatly simplifying both analyses and experiments.

The overall objective of this experiment is to achieve, in cold-flow studies (no ignition or flames), the uniform dispersion and static suspension of coal particles under reduced gravity conditions. Following the successful completion of this model study, beneficial dispersion pattern data will be obtained and used in future research (not part of the present proposed study) where the suspension will be ignited to study the ignition behavior of and flame propagation in coal-particle clouds.

By performing this non-ignition experiment in actual reduced gravity flights, a procedure for attaining an ideal environment for further testing will be developed. The implications of this experiment are far reaching: Knowledge gained from this study can lead to the development of tools and methods used to prevent catastrophes such as explosions in coal mine shafts and grain elevators.

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Last Modified: Tue May 19 1998
CSR/TSGC Team Web