### Abstract

An explicit equation is proposed which predicts directly the terminal velocity of solid spheres falling through stagnant pseudoplastic liquids from the knowledge of the physical properties of the spheres and of the surrounding liquid. The equation is a generalization of the equation proposed for Newtonian liquids. By properly defining the dimensionless diameter, d*, a function of the Archimedes number, Ar, and the dimensionless velocity, U*, a function of the generalized Reynolds number, Re, to account for the non-Newtonian characteristics of the liquid, the final equation relating these two variables has similar form to the Newtonian equation. The predictions are very good when they are compared to 55 pairs of Re - C_{D} for non-Newtonian data and 37 pairs for Newtonian data published previously. The root mean square error on the dimensionless velocity is 0.081 and much better than the only other equation previously proposed.

Original language | English |
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Pages (from-to) | 4437-4447 |

Number of pages | 11 |

Journal | Chemical Engineering Science |

Volume | 59 |

Issue number | 21 |

DOIs | |

Publication status | Published - Nov 2004 |

Externally published | Yes |

### Fingerprint

### Keywords

- Explicit terminal velocity
- Non-Newtonian fluids
- Particle
- Sedimentation
- Slurries
- Suspension

### ASJC Scopus subject areas

- Chemical Engineering(all)

### Cite this

**An explicit equation for the terminal velocity of solid spheres falling in pseudoplastic liquids.** / Kelessidis, Vassilios G.

Research output: Contribution to journal › Article

*Chemical Engineering Science*, vol. 59, no. 21, pp. 4437-4447. https://doi.org/10.1016/j.ces.2004.07.008

}

TY - JOUR

T1 - An explicit equation for the terminal velocity of solid spheres falling in pseudoplastic liquids

AU - Kelessidis, Vassilios G.

PY - 2004/11

Y1 - 2004/11

N2 - An explicit equation is proposed which predicts directly the terminal velocity of solid spheres falling through stagnant pseudoplastic liquids from the knowledge of the physical properties of the spheres and of the surrounding liquid. The equation is a generalization of the equation proposed for Newtonian liquids. By properly defining the dimensionless diameter, d*, a function of the Archimedes number, Ar, and the dimensionless velocity, U*, a function of the generalized Reynolds number, Re, to account for the non-Newtonian characteristics of the liquid, the final equation relating these two variables has similar form to the Newtonian equation. The predictions are very good when they are compared to 55 pairs of Re - CD for non-Newtonian data and 37 pairs for Newtonian data published previously. The root mean square error on the dimensionless velocity is 0.081 and much better than the only other equation previously proposed.

AB - An explicit equation is proposed which predicts directly the terminal velocity of solid spheres falling through stagnant pseudoplastic liquids from the knowledge of the physical properties of the spheres and of the surrounding liquid. The equation is a generalization of the equation proposed for Newtonian liquids. By properly defining the dimensionless diameter, d*, a function of the Archimedes number, Ar, and the dimensionless velocity, U*, a function of the generalized Reynolds number, Re, to account for the non-Newtonian characteristics of the liquid, the final equation relating these two variables has similar form to the Newtonian equation. The predictions are very good when they are compared to 55 pairs of Re - CD for non-Newtonian data and 37 pairs for Newtonian data published previously. The root mean square error on the dimensionless velocity is 0.081 and much better than the only other equation previously proposed.

KW - Explicit terminal velocity

KW - Non-Newtonian fluids

KW - Particle

KW - Sedimentation

KW - Slurries

KW - Suspension

UR - http://www.scopus.com/inward/record.url?scp=4644306738&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=4644306738&partnerID=8YFLogxK

U2 - 10.1016/j.ces.2004.07.008

DO - 10.1016/j.ces.2004.07.008

M3 - Article

VL - 59

SP - 4437

EP - 4447

JO - Chemical Engineering Science

JF - Chemical Engineering Science

SN - 0009-2509

IS - 21

ER -