Inertia Effects on the Flow of Bingham Plastics Through Sudden Contractions in a Pipe

George Vradis, Khaled J. Hammad

Research output: Contribution to journalArticle

Abstract

The present numerical study concentrates on the effects of moderate and high Reynolds numbers on the laminar flow of a non-Newtonian rigid viscoplastic (Bingham) fluid through a sudden contraction in a pipe. The flow is assumed to be steady, incompressible, and isothermal. Results are presented for a wide range of the governing Reynolds and yield numbers and the significant effects of these two parameters both on the integral and local kinematic properties of the flow field are established. Low yield numbers result in the disappearance of the recirculating flow region at the corner replacing it with a region of very low rates of deformation. The evolution of the centerline velocity in the vicinity of the contraction plane is shown to be independent of the yield number and dependent on the Reynolds number, while the concavities in the streamwise velocity profiles appearing at high Reynolds numbers are independent of the yield number. The pressure losses through the contraction increase with yield number with the effect being more pronounced at lower Reynolds numbers.

Original languageEnglish (US)
Pages (from-to)457-463
Number of pages7
JournalCanadian Journal of Chemical Engineering
Volume74
Issue number4
StatePublished - 1996

Fingerprint

Reynolds number
Pipe
Plastics
Laminar flow
Flow fields
Kinematics
Fluids

Keywords

  • Bingham fluids
  • Computational methods
  • Non-Newtonian Fluids
  • Sudden contraction
  • Yield stress

ASJC Scopus subject areas

  • Polymers and Plastics

Cite this

Inertia Effects on the Flow of Bingham Plastics Through Sudden Contractions in a Pipe. / Vradis, George; Hammad, Khaled J.

In: Canadian Journal of Chemical Engineering, Vol. 74, No. 4, 1996, p. 457-463.

Research output: Contribution to journalArticle

@article{3ba72ffccac443a5ba029302d3717105,
title = "Inertia Effects on the Flow of Bingham Plastics Through Sudden Contractions in a Pipe",
abstract = "The present numerical study concentrates on the effects of moderate and high Reynolds numbers on the laminar flow of a non-Newtonian rigid viscoplastic (Bingham) fluid through a sudden contraction in a pipe. The flow is assumed to be steady, incompressible, and isothermal. Results are presented for a wide range of the governing Reynolds and yield numbers and the significant effects of these two parameters both on the integral and local kinematic properties of the flow field are established. Low yield numbers result in the disappearance of the recirculating flow region at the corner replacing it with a region of very low rates of deformation. The evolution of the centerline velocity in the vicinity of the contraction plane is shown to be independent of the yield number and dependent on the Reynolds number, while the concavities in the streamwise velocity profiles appearing at high Reynolds numbers are independent of the yield number. The pressure losses through the contraction increase with yield number with the effect being more pronounced at lower Reynolds numbers.",
keywords = "Bingham fluids, Computational methods, Non-Newtonian Fluids, Sudden contraction, Yield stress",
author = "George Vradis and Hammad, {Khaled J.}",
year = "1996",
language = "English (US)",
volume = "74",
pages = "457--463",
journal = "Canadian Journal of Chemical Engineering",
issn = "0008-4034",
publisher = "Wiley-Liss Inc.",
number = "4",

}

TY - JOUR

T1 - Inertia Effects on the Flow of Bingham Plastics Through Sudden Contractions in a Pipe

AU - Vradis, George

AU - Hammad, Khaled J.

PY - 1996

Y1 - 1996

N2 - The present numerical study concentrates on the effects of moderate and high Reynolds numbers on the laminar flow of a non-Newtonian rigid viscoplastic (Bingham) fluid through a sudden contraction in a pipe. The flow is assumed to be steady, incompressible, and isothermal. Results are presented for a wide range of the governing Reynolds and yield numbers and the significant effects of these two parameters both on the integral and local kinematic properties of the flow field are established. Low yield numbers result in the disappearance of the recirculating flow region at the corner replacing it with a region of very low rates of deformation. The evolution of the centerline velocity in the vicinity of the contraction plane is shown to be independent of the yield number and dependent on the Reynolds number, while the concavities in the streamwise velocity profiles appearing at high Reynolds numbers are independent of the yield number. The pressure losses through the contraction increase with yield number with the effect being more pronounced at lower Reynolds numbers.

AB - The present numerical study concentrates on the effects of moderate and high Reynolds numbers on the laminar flow of a non-Newtonian rigid viscoplastic (Bingham) fluid through a sudden contraction in a pipe. The flow is assumed to be steady, incompressible, and isothermal. Results are presented for a wide range of the governing Reynolds and yield numbers and the significant effects of these two parameters both on the integral and local kinematic properties of the flow field are established. Low yield numbers result in the disappearance of the recirculating flow region at the corner replacing it with a region of very low rates of deformation. The evolution of the centerline velocity in the vicinity of the contraction plane is shown to be independent of the yield number and dependent on the Reynolds number, while the concavities in the streamwise velocity profiles appearing at high Reynolds numbers are independent of the yield number. The pressure losses through the contraction increase with yield number with the effect being more pronounced at lower Reynolds numbers.

KW - Bingham fluids

KW - Computational methods

KW - Non-Newtonian Fluids

KW - Sudden contraction

KW - Yield stress

UR - http://www.scopus.com/inward/record.url?scp=0030208692&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030208692&partnerID=8YFLogxK

M3 - Article

VL - 74

SP - 457

EP - 463

JO - Canadian Journal of Chemical Engineering

JF - Canadian Journal of Chemical Engineering

SN - 0008-4034

IS - 4

ER -