Drag reduction and heat transfer of surfactants flowing in a capillary tube

Hetsroni, G.; Gurevich, Maxim; Mosyak, A.; Rozenblit, R.

doi:10.1016/j.ijheatmasstransfer.2004.03.009

Cited by 37 publications

(22 citation statements)

References 30 publications

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“…In the laminar regime they found a net increase and a dependence of the Nusselt number on roughness at diameters smaller than 1 mm and Ra/D values larger than 0.3%. Hetsroni et al (2004), on the other hand, observed a sharp decrease in the fully developed Nusselt number at Reynolds numbers below 100, doing experiments on a 1.07 mm smooth tube. For Re > 400 the heat transfer number tended towards the theoretical value; this evidenced a clear effect of axial conduction along the channel wall, which is amplified at lower fluid mass fluxes.…”

Section: Introductionmentioning

confidence: 98%

Single-phase laminar and turbulent heat transfer in smooth and rough microtubes

Celata

Cumo

McPhail

et al. 2007

Microfluid Nanofluid

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An experimental campaign was carried out studying laminar and turbulent heat transfer in uniformly heated smooth glass and rough stainless steel microtubes from 0.5 mm down to 0.12 mm. Heat transfer in turbulent regime proved to be coherent-within experimental accuracy-with the classic Gnielinski correlation for the Nusselt number. For the laminar case, an anomalous drop in Nusselt number for decreasing Reynolds number was observed in the smooth glass tubes. As the stainless steel tubes manifested relatively normal diabatic behaviour in this regime (apart from the evident influence of the thermal development region that increases heat transfer above the thermally fully developed value), the explanation of this unexpected diminution of the Nusselt number must be sought in the dispersion of heat, put in externally through the thin film deposited on the glass tube outer surface, to peripheral attachments to the test section. This distorts the measured energy balance of the experiment, especially as the convective force of the fluid diminishes, resulting in lower Nusselt numbers at lower Reynolds numbers.

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Section: Introductionmentioning

confidence: 98%

Single-phase laminar and turbulent heat transfer in smooth and rough microtubes

Celata

Cumo

McPhail

et al. 2007

Microfluid Nanofluid

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“…Also, although the average Nusselt <Nu> decreases asymptotically, the asymptote is smaller than predicted theoretically. Hetsroni et al [27], Choi et al [28] and Tso and Mahulicar [29] used a similar representation and associated this behavior with viscous dissipation effects accounted by the Brinkman number (Br = µ.u 2 m /k∆T). However, for the experimental range of Reynolds number, the effect of Brinkman number is not significant (Br < 10 -05 ) and can, therefore, be ignored.…”

Section: Resultsmentioning

confidence: 99%

Friction Losses and Heat Transfer in Laminar Microchannel Single-Phase Liquid Flow

́rio

Moreira

2008

ASME 2008 6th International Conference on Nanochannels, Microchannels, and Minichannels

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Many studies addressed the validity of macroscale theories to describe momentum and heat transfer in single phase in microtubes, but the results are often inconsistent. It is suggested that the fluid flow and heat transfer in microchannels without phase change is substantially different from that in larger channels. However, these discrepancies may be attributed to experimental uncertainties mainly due to the use of conventional measurement apparatus that are too big to implement in the tested system. Other researchers explain the microfluidic behavior with the ratio of surface forces to body forces which evolve inversely to the hydraulic diameter. The present work considers the use of a dedicated experimental facility built to allow the use of optical diagnostic and flow visualization techniques in heated microtubes and addresses the potential microscale effects which may arise for single phase flow conditions.The experiments encompass measurements of the pressure drop and the longitudinal temperature distribution in the fully developed single phase liquid flow established in circular and square cross section of channels made of borosilicate glass with hydraulic diameters from 50µm up to 500µm. The flow conditions consider a range of Reynolds number from 10 up to around 2500 and the use of diverse fluids to account for the effects of liquid properties. Namely, three distinct fluids were used: distilled water, methoxy-nonafluorobutane and methanol.For heat transfer studies, the channels are heated with constant wall heat flux supplied by Joule effect by means of external wall rf-PERTE deposition of Indium Oxide thin film. The thin transparent film showed good chemical stability in the range of temperatures up to 70ºC, therefore indicating that the thermal boundary condition approximates a constant wall heat flux condition.The mass flux is varied from 60 to 3300kg.m -2 .s -1 and the heat flux was set between 4 and 6kW.m -2 .Experimental uncertainties are estimated to be below 14% for the friction factor and below 24% for Nusselt number; the former is dominated by inaccuracies in the diameter, while the second is dominated by temperature measurements.Downloaded From: http://proceedings.asmedigitalcollection.asme.org/ on 06/15/2015 Terms of Use: http://asme.org/terms

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“…Drag reduction in a surfactant solution flowing in a micro-channel was the subject of experimental study by Hetsroni et al (2004). The pressure drop in fully developed laminar flow in a micro-tube of inner diameter 1.07 mm was measured in the range of 10 ≤ Re ≤ 450.…”

Section: Surfactant Solutionsmentioning

confidence: 99%

Velocity Field and Pressure Drop in Single-Phase Flows

2009

Heat and Mass Transfer

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The available experimental data on the flow of incompressible fluids are generalized. These data encompass a wide range of Reynolds numbers that correspond to laminar, transient and turbulent regimes of the flow. Thermal effects due to energy dissipation are estimated. Laminar drag reduction in micro-channels using hydrophobic surfaces is discussed. Data of experimental investigations related to the flow in smooth and rough micro-channels are compared with predictions of the conventional theory. Possible sources of divergence of experimental and theoretical results are also discussed. L.P. Yarin, Fluid Flow, Heat Transfer and Boiling in Micro-Channels

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Drag reduction and heat transfer of surfactants flowing in a capillary tube

Cited by 37 publications

References 30 publications

Single-phase laminar and turbulent heat transfer in smooth and rough microtubes

Single-phase laminar and turbulent heat transfer in smooth and rough microtubes

Friction Losses and Heat Transfer in Laminar Microchannel Single-Phase Liquid Flow

Velocity Field and Pressure Drop in Single-Phase Flows

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