### Abstract

The apparent viscosities of purely viscous non-Newtonian fluids are shear rate dependent. At low shear rates, many of such fluids exhibit Newtonian behaviour while at higher shear rates non-Newtonian, power law characteristics exist. Between these two ranges, the fluid's viscous properties are neither Newtonian or power law. Utilizing an apparent viscosity constitutive equation called the "Modified Power Law" which accounts for the above behavior, solutions have been obtained for forced convection flows. A shear rate similarity parameter is identified which specifies both the shear rate range for a given fluid and set of operating conditions and the appropriate solution for that range. The results of numerical solutions for the friction factor-Reynolds number product and for the Nusselt number as a function of a dimensionless shear rate parameter have been presented for forced fully developed laminer duct flows of different cross-sections with modified power law fluids. Experimental data is also presented showing the suitability of the "Modified Power Law" constitutive equation to represent the apparent viscosity of various polymer solutions.

Original language | English |
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Pages (from-to) | 141-149 |

Number of pages | 9 |

Journal | Heat and Mass Transfer/Waerme- und Stoffuebertragung |

Volume | 38 |

Issue number | 1 |

Publication status | Published - 2002 Jan 1 |

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### ASJC Scopus subject areas

- Fluid Flow and Transfer Processes
- Physical and Theoretical Chemistry
- Computational Mechanics
- Mechanics of Materials

### Cite this

**Anomalous predictions of pressure drop and heat transfer in ducts of arbitrary cross-section with modified power law fluids.** / Park, Simsoo; Lee, D. R.

Research output: Contribution to journal › Article

*Heat and Mass Transfer/Waerme- und Stoffuebertragung*, vol. 38, no. 1, pp. 141-149.

}

TY - JOUR

T1 - Anomalous predictions of pressure drop and heat transfer in ducts of arbitrary cross-section with modified power law fluids

AU - Park, Simsoo

AU - Lee, D. R.

PY - 2002/1/1

Y1 - 2002/1/1

N2 - The apparent viscosities of purely viscous non-Newtonian fluids are shear rate dependent. At low shear rates, many of such fluids exhibit Newtonian behaviour while at higher shear rates non-Newtonian, power law characteristics exist. Between these two ranges, the fluid's viscous properties are neither Newtonian or power law. Utilizing an apparent viscosity constitutive equation called the "Modified Power Law" which accounts for the above behavior, solutions have been obtained for forced convection flows. A shear rate similarity parameter is identified which specifies both the shear rate range for a given fluid and set of operating conditions and the appropriate solution for that range. The results of numerical solutions for the friction factor-Reynolds number product and for the Nusselt number as a function of a dimensionless shear rate parameter have been presented for forced fully developed laminer duct flows of different cross-sections with modified power law fluids. Experimental data is also presented showing the suitability of the "Modified Power Law" constitutive equation to represent the apparent viscosity of various polymer solutions.

AB - The apparent viscosities of purely viscous non-Newtonian fluids are shear rate dependent. At low shear rates, many of such fluids exhibit Newtonian behaviour while at higher shear rates non-Newtonian, power law characteristics exist. Between these two ranges, the fluid's viscous properties are neither Newtonian or power law. Utilizing an apparent viscosity constitutive equation called the "Modified Power Law" which accounts for the above behavior, solutions have been obtained for forced convection flows. A shear rate similarity parameter is identified which specifies both the shear rate range for a given fluid and set of operating conditions and the appropriate solution for that range. The results of numerical solutions for the friction factor-Reynolds number product and for the Nusselt number as a function of a dimensionless shear rate parameter have been presented for forced fully developed laminer duct flows of different cross-sections with modified power law fluids. Experimental data is also presented showing the suitability of the "Modified Power Law" constitutive equation to represent the apparent viscosity of various polymer solutions.

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M3 - Article

VL - 38

SP - 141

EP - 149

JO - Heat and Mass Transfer

JF - Heat and Mass Transfer

SN - 0947-7411

IS - 1

ER -