### Abstract

Original language | English |
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Pages (from-to) | 177-182 |

Number of pages | 6 |

Journal | International Communications in Heat and Mass Transfer |

Volume | 88 |

Early online date | 26 Sep 2017 |

DOIs | |

Publication status | Published - Nov 2017 |

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### Cite this

*International Communications in Heat and Mass Transfer*,

*88*, 177-182. https://doi.org/10.1016/j.icheatmasstransfer.2017.09.003

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*International Communications in Heat and Mass Transfer*, vol. 88, pp. 177-182. https://doi.org/10.1016/j.icheatmasstransfer.2017.09.003

**Asymptotic Analyses of the Start-Up Stage of Couette Flow Subjected to Different Boundary Conditions.** / Lei, Chen; Liu, Gang; Zhang, Guozhong; Tang, Yuannan ; Chai, John.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Asymptotic Analyses of the Start-Up Stage of Couette Flow Subjected to Different Boundary Conditions

AU - Lei, Chen

AU - Liu, Gang

AU - Zhang, Guozhong

AU - Tang, Yuannan

AU - Chai, John

PY - 2017/11

Y1 - 2017/11

N2 - In this article, the process for reaching “developed” stage was investigated under both imposed shear stress and specified velocity boundary conditions. Four specific situations are investigated. These are (1) constant shear stress, (2) linearly increasing shear stress from zero shear, (3) constant velocity and (4) linearly increasing velocity from stationary. Analytical solutions of velocity distributions under these four situations were obtained. A dimensionless viscosity, defined as the ratio of the measured viscosity calculated based on the measuring principle of Couette-type viscometer to the true viscosity of fluid was proposed to describe the initial transient period. We define the “developed” stage when the dimensionless viscosity is 1% away from its final value or when it reaches 1.01. By analyzing Stokes’ first problem, compact models of the dimensionless viscosity were expressed and exact quantitative relations among the initial values of dimensionless viscosity under these four specific situations were found. Time periods for Couette flow to reach the “developed” stage was calculated. The development time is the shortest under the constant velocity boundary and is the longest under the linearly increasing shear stress boundary.

AB - In this article, the process for reaching “developed” stage was investigated under both imposed shear stress and specified velocity boundary conditions. Four specific situations are investigated. These are (1) constant shear stress, (2) linearly increasing shear stress from zero shear, (3) constant velocity and (4) linearly increasing velocity from stationary. Analytical solutions of velocity distributions under these four situations were obtained. A dimensionless viscosity, defined as the ratio of the measured viscosity calculated based on the measuring principle of Couette-type viscometer to the true viscosity of fluid was proposed to describe the initial transient period. We define the “developed” stage when the dimensionless viscosity is 1% away from its final value or when it reaches 1.01. By analyzing Stokes’ first problem, compact models of the dimensionless viscosity were expressed and exact quantitative relations among the initial values of dimensionless viscosity under these four specific situations were found. Time periods for Couette flow to reach the “developed” stage was calculated. The development time is the shortest under the constant velocity boundary and is the longest under the linearly increasing shear stress boundary.

KW - Couette flow

KW - Boundary conditions

KW - Development time

KW - Dimensionless viscosity

UR - http://www.sciencedirect.com/science/journal/07351933?sdc=1

U2 - 10.1016/j.icheatmasstransfer.2017.09.003

DO - 10.1016/j.icheatmasstransfer.2017.09.003

M3 - Article

VL - 88

SP - 177

EP - 182

JO - International Communications in Heat and Mass Transfer

JF - International Communications in Heat and Mass Transfer

SN - 0735-1933

ER -