Pipe flow of a thixotropic liquid

Escudier, M. P.; Presti, Federico Lo

doi:10.1016/0377-0257(96)01417-6

Cited by 89 publications

(122 citation statements)

References 13 publications

Supporting

Mentioning

107

Contrasting

Order By: Relevance

“…An electromagnetic flowmeter [14] (Fischer and Porter model 10 D1) is incorporated in the return arm of the flow loop, with the output signal recorded via an analog-todigital converter (Amplicon PS 30 AT) on a PC (IBM AT286). Flow rates indicated by the flowmeter were within 1% of values computed from velocity profiles measured in pipe flow (Escudier and Presti 1996) using the LDA system, which is a measure of the overall accuracy of the measurements. In-house software was written to record flowrate, pressure drop, and fluid temperature and to control and record traverse location.…”

Section: Experimental Rig Instrumentation and Test Liquidmentioning

confidence: 65%

Fully developed laminar flow of non-Newtonian liquids through annuli: comparison of numerical calculations with experiments

et al. 2002

View full text Add to dashboard Cite

Experimental data are reported for fully developed laminar flow of a shear-thinning liquid through both a concentric and an 80% eccentric annulus with and without centrebody rotation. The working fluid was an aqueous solution of 0.1% xanthan gum and 0.1% carboxymethylcellulose for which the flow curve is well represented by the Cross model. Comparisons are reported between numerical calculations and the flow data, as well as with other laminar annular-flow data for a variety of shear-thinning liquids previously reported in the literature. In general, the calculations are in good quantitative agreement with the experimental data, even in situations where viscoelastic effects, neglected in the calculations, would be expected to play a role.

show abstract

Section: Experimental Rig Instrumentation and Test Liquidmentioning

confidence: 65%

Fully developed laminar flow of non-Newtonian liquids through annuli: comparison of numerical calculations with experiments

et al. 2002

View full text Add to dashboard Cite

show abstract

“…The 1.5% suspension and the blend were selected to allow comparison with the works of Escudier et al (1992Escudier et al ( , 1996. Blending laponite with CMC (sodium carboxymethyl cellulose) is suggested also by the manufacturer of laponite (see Laponite, 1979) as a way to increase the gel strength and its shear viscosity.…”

Section: The Fluidsmentioning

confidence: 99%

“…Some such works are the LDA measurements of Park et al (1989) with an oil-based transparent slurry with yield stress obeying the Herschel-Bulkley law and the more recent investigations of Escudier et al (1992Escudier et al ( , 1996. Escudier and Presti (1996) and Escudier et al (1992) used transparent aqueous suspensions based on laponite and a mixture of laponite and a polymer, respectively. Park et al used silica particles suspended in a mixture of Stoddard solvent and mineral oil and reported on a time-independent, yield stress fluid following theory in laminar flow and a behaviour similar to that of Laufer (1954) in the turbulent flow regime.…”

Section: Introductionmentioning

confidence: 99%

“…For both cases, shear-thinning fluids with yield stress obeying the Herschel-Bulkley law were selected, but whereas in Park et al the fluid was time independent, the laponite suspensions exhibited thixotropy. In Escudier and Presti (1996) the flow field was investigated in detail in the laminar, transitional and turbulent flow regimes. They could only predict accurately the laminar pipe flow with the Herschel-Bulkley model fitted to the velocity profiles, i.e., indirectly to the viscosity data at the prevailing flow conditions, rather than to the equilibrium state viscosity data.…”

Section: Introductionmentioning

confidence: 99%

“…The pipe has a diameter of 26 mm and the diameter effect is investigated by comparing the results with those from the 100.8 mm diameter pipe of Escudier and Presti (1996).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Turbulent pipe flow of thixotropic fluids

Pereira¹,

Pinho

2002

International Journal of Heat and Fluid Flow

View full text Add to dashboard Cite

The conundrum of migraine headaches in the presence of patent foramen ovale

Tobis

2009

Cathet Cardio Intervent

View full text Add to dashboard Cite

The accompanying article by the interventional group in Geneva describes their experience in 17 patients who had their PFO closed solely for the indication of severe migraine headaches. This is distinct from most prior observational studies that describe the effect on migraine headache of PFO closure when the procedure was performed primarily to prevent recurrent stroke or decompression illness. Approximately 70% of the patients in this study had a significant decrease or complete abolition (in 24% of cases) of migraine headaches. This current report supplements a recent report by Vigna et al., which describes a positive experience with PFO closure in 53 patients who had migraine headaches and white matter lesions [1]. In that study, the mean number of migraine attacks decreased from 32 to 7 over a 6-month follow up period in the patients who had PFO closure, compared to no significant change in the patients who chose not to have their PFO closed.The observational data obtained from these recent reports, in conjunction with prior observations in cryptogenic stroke patients, is very consistent. Unfortunately, the only randomized controlled trial to date evaluating the effectiveness of PFO closure for migraine headache treatment, the MIST Trial, did not show significant improvement. However, it is believed that a significant proportion of patients in the MIST Trial had a residual shunt after device insertion, likely due to inadequate closure provided by the Starflex device. In addition, the characteristics of the patient population may be different between those included in the MIST Trial and the observational reports, including the present one from Geneva. I hope neurologists consider all the evidence that is currently available and maintain an open position with respect to the association of migraine headaches and patent foramen ovale.There are multiple questions that remain concerning PFO closure and migraine. For instance, we still have not identified which characteristics predict the patients likely to respond to PFO closure. Will the responders include only those with visual aura? Approximately 75% of patients with migraine with aura have a significant benefit from PFO closure, but we have seen about 30% of the patients with migraine without aura who also responded to PFO closure [2]. Are the responders more likely to have transient neurologic deficits (which are frequently misdiagnosed as transient ischemic attacks but actually are complex migraine)? Or should we be concentrating on the patient population that already has evidence of brain involvement; that is, those people with white matter lesions on MRI?Although the majority (60%) of patients screened in the MIST trial had a right to left shunt, there clearly are many people with migraine who do not have a PFO or other etiology of a right to left shunt. In addition, not everyone with a PFO and migraines responds to PFO closure. Nevertheless, as physicians, we are struck by the enormous amount of suffering that patients with frequent migraine must endure. ...

show abstract

Pipe flow of a thixotropic liquid

Cited by 89 publications

References 13 publications

Fully developed laminar flow of non-Newtonian liquids through annuli: comparison of numerical calculations with experiments

Fully developed laminar flow of non-Newtonian liquids through annuli: comparison of numerical calculations with experiments

Turbulent pipe flow of thixotropic fluids

The conundrum of migraine headaches in the presence of patent foramen ovale

Contact Info

Product

Resources

About