Falling coaxial cylinder viscometer with wide shear rate range

1977 ◽  
Vol 16 (6) ◽  
pp. 635-642 ◽  
Author(s):  
K. K. Chee ◽  
A. Rudin
Keyword(s):  
Shear Rate ◽  
Coaxial Cylinder ◽  
Rate Range ◽  
Cylinder Viscometer

Flow behaviour of low solids fresh cheeses

1993 ◽  
Vol 60 (4) ◽  
pp. 593-601 ◽  
Author(s):  
Jozef Korolczuk
Keyword(s):  
Shear Rate ◽  
Initial Level ◽  
Coaxial Cylinder ◽  
Initial Value ◽  
Exponential Equation ◽  
Final Stress ◽  
Final Yield ◽  
Time Required ◽  
Rate Relation ◽  
Cylinder Viscometer

SummaryA computerized, coaxial cylinder viscometer, controlled by a function synthesizer, was used to study the stress characteristics of acid fresh cheeses containing 7·5–8·5% protein and 0–20% fat in total solids, as a function of shearing time (0–3600 s) and of shear rate (0–4·5 s–1). For a given shear rate the stress diminished with time, following an exponential equation. The hypothetical final stress level (Sf for the shearing time t = ∞) represented about half its initial value (Si). For four cheese samples, the time required for the stress to become equal to Sf + (Sf – Sf)/e was 340–560 s. The stress-shear rate relation indicated shear thinning behaviour. The effect of shearing time showed that the material was thixotropic. The cheeses exhibited plastic flow. The initial and final stress levels were hyperbolic functions of the shear rate. Bingham final yield stress (for t = ∞) was 14–50 Pa. It was 15–25% higher for increasing than for decreasing shear rate. Bingham viscosity (for t = ∞) was between 2 and 6 Pa s. It was 10–20% higher for decreasing shear rate. The initial level of Bingham viscosity was ˜ 30% higher than its final value.

Further remarks on falling coaxial cylinder with wide shear rate range

1978 ◽  
Vol 17 (3) ◽  
pp. 312-313
Author(s):  
A. Rudin ◽  
C. K. Ober ◽  
K. K. Chee
Keyword(s):  
Shear Rate ◽  
Coaxial Cylinder ◽  
Rate Range

Estimation of Red Cell Deformability Based on Flow Curve of Whole Blood in the Higher Shear Rate Range.

2001 ◽  
Vol 27 (2) ◽  
pp. 228-235
Author(s):  
Shinichi Ookawara ◽  
Akihisa Yano ◽  
Kohei Ogawa ◽  
Koichi Taniguchi
Keyword(s):  
Shear Rate ◽  
Whole Blood ◽  
Flow Curve ◽  
Red Cell ◽  
Cell Deformability ◽  
Red Cell Deformability ◽  
Rate Range

Flow Properties of Utah Shale Oils

1981 ◽  
Vol 21 (06) ◽  
pp. 679-686 ◽  
Author(s):  
W.H. Seitzer
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Pour Point ◽  
Water Solution ◽  
Shale Oil ◽  
Concentric Cylinder ◽  
Long Distance ◽  
Time Calibration ◽  
The Difference ◽  
Cylinder Viscometer

Abstract In a concentric cylinder viscometer. Utah shale oils have different characteristics, both at equilibrium flow and during start-up from rest, depending on whether the wax has crystallized as needles or spherulites. Compared with waxy crude oils, which are thixotropic, shale oil had the added rheological property of being antithixotropic. Introduction The most likely liquid synthetic fuel to be produced initially in the U.S. will be raw shale oil from western oil shale. This abundant resource is located principally in the western Rocky Mountain states of Colorado. Utah. and Wyoming (Fig. 1). Ultimate commercial production probably will be transported to marketing, distribution, and refining centers by pipeline. It has been reported that Utah shale oils produced by the Union "B" and Paraho DH retorting processes gave similar physical and chemical properties. Some properties of the two Utah shale oils are given in Table 1. The only major difference is that the Union shale oil has a pour point of - 1 degree C compared with a pour point of 25 degrees C for the Paraho oil. Wax Crystallization The difference in the pour points of the oils from the Utah shale retorted by Union Oil Co of California and Paraho is caused mainly by the difference in how the wax in the respective oils crystallizes. In the high- pour-point (25 degrees C) Paraho DK oil, the wax, under a microscope, appears as fine (1 to 10 m) needles, as expected for normal paraffins. However, the wax in the low-pour-point (−1 degrees C) Union oil forms small spherulites.Wax spherulites have not been reported before: however, this type of crystal is seen commonly in polymer. Spherulites show up as round areas containing a maltese cross when observed between crossed polars under a microscope.Photomicrographs of these crystals are shown in Figs. 2 and 3. The former, showing spherulites, is of the Union oil. In contrast, they are very different from the customary needles as typified by the Paraho oil in the latter micrograph. Presumably, these highly ordered spheres are made up of wax needles grown out radially from the center as described by Hartshorne and Stuart. The polarized light is scattered only by those needles not parallel nor perpendicular to the plane of polarization. Viscometer Measurements To understand the effect of these spherulites on the flow characteristics of raw shale oil at flow conditions expected in a long-distance pipeline, typical stress-rate measurements were made in a rotating cylinder viscometer, the Haake Rotovisco RV3 with MK500 measuring head and MVI coaxial cylinder sensor having an 82-mm cup and radii ratio of 0.95. This equipment has provisions for varying shear rate continuously at selected values down to 23.4 sec(−1)/min and can produce and record shear stress as a function of either shear rate or time. Calibration of the sensor was verified with a sucrose/water solution at several temperatures.Changes in temperature always were made from lower to higher to keep the sensor full of oil. Also, the shear-stress/ shear-rate curves were obtained by starting at high shear, down to zero, and then back up. SPEJ P. 679^

A rotational double coaxial cylinder viscometer

1972 ◽  
Vol 11 (3-4) ◽  
pp. 275-285 ◽  
Author(s):  
B. Enoksson
Keyword(s):  
Coaxial Cylinder ◽  
Cylinder Viscometer

Rheological Properties of an Electrorheological Fluid in Original Transition Zone

1999 ◽  
Vol 13 (14n16) ◽  
pp. 1893-1900
Author(s):  
Fan Zhikang ◽  
Liang Shuhua ◽  
Xue Xu ◽  
Wang Gang
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Transition Zone ◽  
Electrorheological Fluid ◽  
Concentric Cylinder ◽  
Pseudoplastic Fluid ◽  
Applied Fields ◽  
Er Fluid ◽  
Regressive Analysis ◽  
Cylinder Viscometer

The rheological properties of an electrorheological(ER) fluid have been studied in a modified concentric cylinder viscometer. The results show that the relation of shear rate and shear stress is non-linear at certain shear rate defined as an original transition zone. Regressive analysis reveals that the ER fluid is of yield-pseudoplastic fluid in the transition zone. With increase in applied fields, the rheological properties of the ER fluid deviates from Newtonian fluid and the length of the transition zone becomes longer.

Flow of Greases Under the Action of Complex Shear

1968 ◽  
Vol 90 (3) ◽  
pp. 604-607 ◽  
Author(s):  
G. V. Vinogradov ◽  
A. A. Mamakov
Keyword(s):  
Shear Stress ◽  
Axial Direction ◽  
Coaxial Cylinder ◽  
Great Decrease ◽  
Annular Space ◽  
Uniform Shear ◽  
Complex Shear ◽  
Shear Stress Field ◽  
Limiting Value ◽  
Cylinder Viscometer

Experiments were performed in a coaxial cylinder viscometer in which there were realized separately and simultaneously flows of grease and bright stock (Newtonian fluid) in the axial and peripheral direction. The latter was at uniform shear stress field. The effect of peripheral on axial-flows was a great decrease in resistance toward deformation in the axial direction. This is a very important peculiarity of greases, which are non-Newtonian media, when considering their flow in labyrinth boxes and some other devices. The effect of axial on peripheral flow showed somewhat increased resistance toward the latter. Such behavior was attributed to continuous inflow of fresh grease into the annular space where it did not remain long enough for structural destruction to reach a limiting value.

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