### Abstract

Although the flow behavior of polymer melts and solutions can generally be adequately described by differential and integral constitutive equations, it is often difficult to obtain solutions to the equations of motion using such constitutive models. Consequently, simpler rheological models are sometimes used to gain some physical insight and at least some qualitative information about the nature of non-Newtonian flows. The generalized Newtonian fluid can be used to study nonlinear viscous effects, and the second-order fluid can be used to study elastic effects in steady flows. Here, we illustrate how a first-order fluid model can be used to study elastic effects in unsteady flows. Solutions for velocity-driven and pressure-driven flows illustrate that the first-order fluid model does describe some of the effects caused by the elasticity of the fluid.

Original language | English (US) |
---|---|

Pages (from-to) | 3203-3207 |

Number of pages | 5 |

Journal | Industrial and Engineering Chemistry Research |

Volume | 34 |

Issue number | 10 |

DOIs | |

State | Published - Oct 1 1995 |

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### All Science Journal Classification (ASJC) codes

- Chemistry(all)
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering

### Cite this

*Industrial and Engineering Chemistry Research*,

*34*(10), 3203-3207. https://doi.org/10.1021/ie00037a004

}

*Industrial and Engineering Chemistry Research*, vol. 34, no. 10, pp. 3203-3207. https://doi.org/10.1021/ie00037a004

**Unsteady Flows of First-Order Fluids.** / Vrentas, James S.; Vrentas, Christine M.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Unsteady Flows of First-Order Fluids

AU - Vrentas, James S.

AU - Vrentas, Christine M.

PY - 1995/10/1

Y1 - 1995/10/1

N2 - Although the flow behavior of polymer melts and solutions can generally be adequately described by differential and integral constitutive equations, it is often difficult to obtain solutions to the equations of motion using such constitutive models. Consequently, simpler rheological models are sometimes used to gain some physical insight and at least some qualitative information about the nature of non-Newtonian flows. The generalized Newtonian fluid can be used to study nonlinear viscous effects, and the second-order fluid can be used to study elastic effects in steady flows. Here, we illustrate how a first-order fluid model can be used to study elastic effects in unsteady flows. Solutions for velocity-driven and pressure-driven flows illustrate that the first-order fluid model does describe some of the effects caused by the elasticity of the fluid.

AB - Although the flow behavior of polymer melts and solutions can generally be adequately described by differential and integral constitutive equations, it is often difficult to obtain solutions to the equations of motion using such constitutive models. Consequently, simpler rheological models are sometimes used to gain some physical insight and at least some qualitative information about the nature of non-Newtonian flows. The generalized Newtonian fluid can be used to study nonlinear viscous effects, and the second-order fluid can be used to study elastic effects in steady flows. Here, we illustrate how a first-order fluid model can be used to study elastic effects in unsteady flows. Solutions for velocity-driven and pressure-driven flows illustrate that the first-order fluid model does describe some of the effects caused by the elasticity of the fluid.

UR - http://www.scopus.com/inward/record.url?scp=0029379970&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029379970&partnerID=8YFLogxK

U2 - 10.1021/ie00037a004

DO - 10.1021/ie00037a004

M3 - Article

AN - SCOPUS:0029379970

VL - 34

SP - 3203

EP - 3207

JO - Industrial and Engineering Chemistry Research

JF - Industrial and Engineering Chemistry Research

SN - 0888-5885

IS - 10

ER -