When solid particles are suspended in the fluid and are not in a jammed state, a fruitful approach to modelling the system can be to describe it as a system of particles interacting both with each other and with an external field. In the specific case when the particles are far enough apart, the dominant interactions between particles are those mediated by the surrounding fluid rather than direct particle-particle interactions, possibly only when the particles are touching. One of the most important phenomena observed in this regime is particle roping – rather than being evenly dispersed throughout the fluid, particles congregate in one or more ‘ropes’ aligned with the flow direction. This can be a serious problem in coal fired power stations, which require coal dust to be evenly distributed to operate at maximum efficiency. This thesis presents a basic numerical study of particle-fluid-particle interactions under conditions characteristic of the roping phenomenon found after bends in the pneumatic transport systems of coal fired power plants. The main objectives of this work are to: 1. Obtain a pair potential hydrodynamic force field from computational fluid dynamics (CFD) simulations of two fixed spherical particles at low particle Reynolds number; 2. Estimate the magnitude of errors introduced by the pair potential approximation by comparing the two fixed spherical particles results with CFD simulations of systems of three fixed spherical particles; and 3. Use many-particle Monte Carlo simulations to investigate the conditions under which clustering or roping occurs.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:663188 |
| Date | January 2008 |
| Creators | Vargas-Dilaz, Salvador |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/11500 |
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