The radial distribution of tangential velocity around an impeller has been estimated using laminar flow around a rotating cylinder as a model. A yield stress model for the fluid rheology gave a boundary at which the fluid velocity fell to zero (cavern boundary) which moved outwards with increasing i
Drag models, solids concentration and velocity distribution in a stirred tank
โ Scribed by Aoyi Ochieng; Maurice S. Onyango
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- English
- Weight
- 305 KB
- Volume
- 181
- Category
- Article
- ISSN
- 0032-5910
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โฆ Synopsis
Drag force influences both the particle suspension and solids concentration distribution in a stirred tank. The influence of drag models on the prediction of solids suspension in a tank stirred by a hydrofoil impeller was studied in the present work using computational fluid dynamics (CFD) and experimental techniques. A comparison was made between the drag models based on Reynolds number only and those that take solid volume fraction into account or those that account for the effect of the free stream turbulence. One of the drag models investigated was a function of the energy dissipation rate, and therefore, the influence of the methods of determining the energy dissipation rate on the prediction of solids suspension was investigated. It was shown that a better agreement between the CFD simulation and experimental results can be obtained using drag models based on solids volume fraction than those that are based on Reynolds number only.
๐ SIMILAR VOLUMES
## Abstract This work aims to investigate the influence of the solid concentration in suspension on the contact secondary nucleation rate of sodium bicarbonate crystallization in a stirred tank crystallizer and to show the necessity of a local description of the mixing for a nucleation rate influen