Explicit Formulas for Slip and Fluidity

Mooney, M.

doi:10.1122/1.2116364

Cited by 878 publications

(367 citation statements)

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“…This bubble separation may also explain the viscosity measurements being affected by the tube diameter. Our attempts to determine wall slip following the formal procedure of Mooney (1931) (see also Macosko, 1994) have not been successful, and the reason for this is unclear. Again, bubble segregation is a possible cause of the problem.…”

Section: 7mentioning

confidence: 99%

Gas bubble retention and its effect on waste properties: Retention mechanisms, viscosity, and tensile and shear strengths

Gauglitz¹,

Rassat²,

Powell³

1995

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DISCLAIMERPortions of this document may be illegible in electronic image products. Images are produced from the best available original document. Executive SummarySeveral of the underground nuclear storage tanks at Hanford have been placed on a flammable gas watch list, because the waste is either known or suspected to generate, store, and episodically release flammable gases. Because retention and episodic release of flammable gases from these tanks containing radioactive waste slurries are critical safety concerns, Pacific Northwest Laboratory (PNL)(a) is studying physical mechanisms and waste properties that contribute to the episodic gas release from these storage tanks. This study is being conducted for Westinghouse Hanford Company as part of the PNL Flammable Gas project. Previous investigations have concluded that gas bubbles are retained by the slurry or sludge that has settled at the bottom of the tanks; however, the mechanisms responsible for the retention of these bubbles are not well understood.Understanding the rheological behavior of the waste, particularly of the settled sludge, is critical to characterizing the tendency of the waste to retain gas bubbles and the dynamics of how these bubbles are released from the waste. The presence of gas bubbles is expected to affect the rheology of the sludge, specifically its viscosity and tensile and shear strengths, but essentially no literature data are available to assess the effect of bubbles.The objectives of this study were to conduct experiments and develop theories to understand better how bubbles are retained by slurries and sludges, to measure the effect of gas bubbles on the viscosity of simulated slurries, and to measure the effect of gas bubbles on the tensile and shear strengths of simulated slurries and sludges. In addition to accomplishing these objectives, this study developed correlations, based on the new experimental data, that can be wed in large-scale computations of waste tank physical phenomena.For bubble retention experiments, a new method of creating retained bubbles was developed. Results show that dissolving soluble gases into the interstitial liquid followed by pressure reduction provides a suitable method of creating bubbles for measuring bubble retention in waste. An equilibrium CO, pressure of 2.4 x l(r Pa (20 psig) is sufficient to create good bubble nucleation and growth with slurries composed of water and glass beads. A pressure reduction rate of 6900 Palmin (1 psi/min) provided a controllable experiment.Experiments were completed to further quantify the transition between bubbles that grow by fingering between sludge particles, called dendritic bubbles, and bubbles that grow by displacing the sludge particles, which are referred to as round bubbles. Previously, a Bond number criterion, which is a ratio of gravitational to surface tension forces, was developed to define the transition between the two different mechanisms of bubble growth and retention. In the experiments conducted, the particle size and fluid and particle d...

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Section: 7mentioning

confidence: 99%

Gas bubble retention and its effect on waste properties: Retention mechanisms, viscosity, and tensile and shear strengths

Gauglitz¹,

Rassat²,

Powell³

1995

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“…Rabinowitsch [12] and Mooney [13] developed an expression for the wall shear rate ' γ w = −(du/dr) w independent of §uid properties and thus valid also for nonNewtonian §uids.…”

Section: Herschel Bulkley-extended Generalized Reynolds Numbermentioning

confidence: 99%

Generalized reynolds number for non-newtonian fluids

Madlener¹,

Frey²,

Ciezki³

2009

Progress in Propulsion Physics

102

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An extended version of the generalized Reynolds number was derived to characterize the duct §ow of non-Newtonian gelled §uids of the Herschel Bulkley-Extended (HBE) type. This number allows also estimating the transition from laminar to turbulent §ow conditions. An experimental investigation was conducted with a capillary rheometer for several non-Newtonian gelled §uids to evaluate the introduced HBE-generalized Reynolds number Re gen HBE . A good correlation between the experimental results and the theory could be found for laminar §ow conditions. For one of the examined gelled fuels, the necessary high Reynolds numbers could be realized so that the transition from the laminar to the turbulent §ow regime could be measured. Because of its general description, the HBE-generalized Reynolds number can also be applied to Newtonian liquids as well as to non-Newtonian §uids of the Herschel Bulkley (HB), Ostwald de-Waele (power-law, PL), and Bingham type. Reynolds number for PL- §uids u (r) velocity, m/s u average §ow velocity, m/s

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“…The various experimental methods of determining wall slip velocity can be found in an excellent review by Hatzikiriakos [19]. Classic gap-dependence methods, such as Mooney's method [20] and the sliding plate rheometer [17], need a series of capillaries/slits with different diameters or thicknesses. Flow visualization with optical techniques involves additional equipment, such as tracing particles and specially designed monitoring systems.…”

Section: Wall Slipmentioning

confidence: 99%

Characterization of thermo-rheological behavior of polymer melts during the micro injection moulding process

Zhang

Gilchrist

2012

Polymer Testing

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A bstract: In-line process monitoring and rheological characterization can help to understand the behavior of polymer melt flows during manufacturing and to make injection molding a measurable process for manufacturing high quality parts. This work developed an in-line rheology measurement system using a slit die attached to a micro injection molding machine. A series of dog-bone mold inserts was used to form the slit die with thickness ranging from 600µm to 200µm. Two combined pressure and temperature sensors were embedded into the slit die to measure the pressure drop. Based on the slit flow model, it was found that the viscosity of Pebax melts depends on the slit thickness in the actual injection molding process. The competing effects of wall slip and non-isothermal conditions will determine the melt viscosity. The plastication induced thermo-mechanical history can also influence polymer viscosity, although it is neglected in conventional rheology measurements.

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Explicit Formulas for Slip and Fluidity

Cited by 878 publications

References 0 publications

Gas bubble retention and its effect on waste properties: Retention mechanisms, viscosity, and tensile and shear strengths

Gas bubble retention and its effect on waste properties: Retention mechanisms, viscosity, and tensile and shear strengths

Generalized reynolds number for non-newtonian fluids

Characterization of thermo-rheological behavior of polymer melts during the micro injection moulding process

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