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Inertia Effects on the Flow of Bingham Plastics Through Sudden Contractions in a Pipe
Author(s) -
Vradis George C.,
Hammad Khaled J.
Publication year - 1996
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450740404
Subject(s) - reynolds number , laminar flow , mechanics , bingham plastic , newtonian fluid , pipe flow , mathematics , hele shaw flow , inertia , physics , materials science , classical mechanics , turbulence , thermodynamics , rheology
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.