CAI Pu, WANG Bo. Numerical simulation of multiphase flow field of non-Newtonian fluid in hydrocyclone[J]. CIESC Journal, 2012, (11): 3460-3469.DOI: 10.3969/j.issn.0438-1157.2012.11.012.
The flow behavior of dense non-Newtonian slurry in a hydrocyclone was described by a viscosity correction model.Combined with the Reynolds stress model
the mixture multiphase model and the stochastic Lagrangian particle tracking model
a comprehensive computational fluid dynamics model was established to simulate the multiphase non-Newtonian flow in a hydrocyclone.The validity of the proposed model was verified by the reasonably good agreement between measured and predicted results with the deviation less than 10%.The results showed that the spatial distribution of slurry viscosity was similar to that of slurry density.The particles at a specific size range with zero radial resultant forces had high-speed rotational movement around the locus of zero vertical velocity(LZVV)
resulting in a high density ring in the body.The spatial distribution of dispersed phase depended on the forces applied.For the particles of various sizes
the magnitude of outward centrifugal force was twice that of inward pressure gradient force.The large particles would enter the downward flow and be collected at the underflow.As particle size decreased
the overall inward drag force with varying direction increased exponentially.As a result
some relatively fine particles were pushed towards the air core and escaped from the overflow with the upward flow. Meanwhile
the randomness of such particle movement was enhanced.When particle size was below a critical value
which meant that the fluid drag force on the particles was much larger than centrifugal force and pressure gradient force
the randomness of particle movement was very strong
resulting in a macroscopically uniform distribution.