Heat transfer and rivulet structures formation in a falling thin liquid film locally heated

Kabov, Oleg; Scheid, Benoît; Sharina, Irina A.; Legros, Jean–Claude

doi:10.1016/s1290-0729(02)01361-3

Cited by 81 publications

(45 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…and further (ii) temperature gradients induced within the film, as this undergoes heating or cooling, can result in significant surface tension gradients and give rise to thermocapillary 'Marangoni' instabilities [22][23][24], which will also affect the interfacial, flow and heat transfer processes. Generally thinner films exhibit the largest heat and mass transfer rates, however in very thin films these instabilities can lead to dewetting or dry spot formation, which will degrade the overall heat and mass transfer characteristics.…”

Section: Case Study I: Heated Falling Filmsmentioning

confidence: 99%

Heat transfer augmentation in unsteady conjugate thermal systems – Part II: Applications

Mathie

Nakamura

Markides

2013

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

Many energy conversion and other thermal-fluid systems exhibit unsteady convective heat exchange. In such systems, generic spatiotemporal variations in the flow give rise to variations in the heat flux for a given fluid-solid temperature difference, which can be interpreted as spatiotemporal fluctuations of the instantaneous heat transfer coefficient. These variations can lead to unsteady conjugate heat transfer, in which the exchanged heat flux arises from an interaction between the bulk fluid temperature and the temperature in the solid. Further, the nonlinear coupling between the fluctuating temperature differences and the heat transfer coefficient can lead to an effect we refer to as augmentation, which quantitatively describes the ability of a particular arrangement to have a different time-mean heat flux from the product between the mean heat transfer coefficient and the mean temperature difference across the fluid. It is important to be able to understand and to model in a simple framework the effects of the material properties, the geometry and the character of the heat transfer coefficient on the thermal response of the fluid-solid system, and consequently to predict the overall heat transfer performance of these systems. This paper, which follows on from its predecessor (Mathie and Markides, 2012a), is concerned with the phenomenon of augmentation in simple, one-dimensional, unsteady and conjugate fluid-solid systems. A simple semi-analytical one-dimensional model of heat transfer with a time-varying heat transfer coefficient, which was presented in Mathie and Markides (2012a), is applied herein to two different paradigm problems. Such a model can be an important tool in the design of improved heat exchangers and thermal insulation, through for example, the novel selection of materials to exploit these augmentation effects. The first flow considered is a thin, wavy fluid film flowing over a heated plate. This film flow exhibits a periodic fluctuation in the heat transfer coefficient, that is linked to the wavy interfacial deformations of free surface of the liquid film. The second flow considered concerns the heat transfer behind a backwards-facing step, which exhibits broadband fluctuations in the heat transfer coefficient due to the flow separation and turbulence behind * Corresponding author.

show abstract

Section: Case Study I: Heated Falling Filmsmentioning

confidence: 99%

Heat transfer augmentation in unsteady conjugate thermal systems – Part II: Applications

Mathie

Nakamura

Markides

2013

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

show abstract

“…In experiments, the control parameter that determines the Nusselt film thicknessh N is the specific volumetric flow rateq N (Kapitza & Kapitza 1949;Liu et al 1993;Kabov et al 2002). We denote its dimensionless form by q N =q N /ν.…”

Section: The Benney Equationmentioning

confidence: 99%

Validity domain of the Benney equation including the Marangoni effect for closed and open flows

Scheid¹,

Ruyer-Quil²,

Thiele³

et al. 2005

J. Fluid Mech.

View full text Add to dashboard Cite

The Benney equation including thermocapillary effects is considered to study a liquid film flowing down a homogeneously heated inclined wall. The link between finite-time blow-up of the Benney equation and absence of one-hump travelling-wave solution of the associated dynamical system is accurately demonstrated in the whole range of linearly unstable wavenumbers. Then the blow-up boundary is tracked in the whole space of parameters accounting for flow rate, surface tension, inclination and thermocapillarity. Especially, the latter two effects can strongly reduce the validity range of the Benney equation. It is also shown that the subcritical bifurcation found for falling films with the Benney equation is related to the blow-up of solutions and is unphysical in any case, even with the thermocapillary effect, in contrast with horizontally heated films. The accuracy of bounded solutions of the Benney equation is also analysed by comparison with a reference weighted integral boundary layer model. A distinction is made between closed and open flow conditions, when calculating travelling-wave solutions; the former corresponding to the conservation of mass and the latter to the conservation of flow rate. The open flow condition matches experimental conditions more closely and is explored for the first time through the associated dynamical system. It yields bounded solutions for larger Reynolds numbers than the closed flow condition. Finally, solutions that are conditionally bounded are found to be unstable to disturbances of larger periodicity. In this case, coalescence is the pathway yielding finite-time blow-up.

show abstract

“…The authors' studies in [6][7][8][9] were focused on underheated thin fluid films flowing down through a locally heated plate. Forced flow of dielectric liquids, with intense evaporation in the minichannel, is a promising solution for cooling modern semiconductor devices for terrestrial and space applications [10].…”

Section: Introductionmentioning

confidence: 99%

The heat transfer crisis in shear driven liquid film of FC-72 by gas flow in a minichannel

Cheverda

2017

EPJ Web Conf.

View full text Add to dashboard Cite

show abstract

Heat transfer and rivulet structures formation in a falling thin liquid film locally heated

Cited by 81 publications

References 2 publications

Heat transfer augmentation in unsteady conjugate thermal systems – Part II: Applications

Heat transfer augmentation in unsteady conjugate thermal systems – Part II: Applications

Validity domain of the Benney equation including the Marangoni effect for closed and open flows

The heat transfer crisis in shear driven liquid film of FC-72 by gas flow in a minichannel

Contact Info

Product

Resources

About