NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Error analysis for reducing noisy wide-gap concentric cylinder rheometric data for nonlinear fluids - Theory and applicationsThis work discusses the propagation of errors for the recovery of the shear rate from wide-gap concentric cylinder viscometric measurements of non-Newtonian fluids. A least-square regression of stress on angular velocity data to a system of arbitrary functions is used to propagate the errors for the series solution to the viscometric flow developed by Krieger and Elrod (1953) and Pawlowski (1953) ('power-law' approximation) and for the first term of the series developed by Krieger (1968). A numerical experiment shows that, for measurements affected by significant errors, the first term of the Krieger-Elrod-Pawlowski series ('infinite radius' approximation) and the power-law approximation may recover the shear rate with equal accuracy as the full Krieger-Elrod-Pawlowski solution. An experiment on a clay slurry indicates that the clay has a larger yield stress at rest than during shearing, and that, for the range of shear rates investigated, a four-parameter constitutive equation approximates reasonably well its rheology. The error analysis presented is useful for studying the rheology of fluids such as particle suspensions, slurries, foams, and magma.
Document ID
19930066496
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Borgia, Andrea (JPL Pasadena, CA, United States)
Spera, Frank J. (California Univ. Santa Barbara, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1990
Publication Information
Publication: Journal of Rheology
Volume: 34
Issue: 1
ISSN: 0148-6055
Subject Category
ENGINEERING (GENERAL)
Funding Number(s)
CONTRACT_GRANT: NSF EAR-88-16103
CONTRACT_GRANT: NAGW-1452
Distribution Limits
Public
Copyright
Other