Evaporation of laminar falling liquid film along an inclined wall
01 Dec 1975-Vol. 8, Iss: 4, pp 241-247
TL;DR: In this paper, an analytical investigation of evaporation of laminar falling liquid film along an inclined wall is presented, and the results for temperature distribution, local heat and mass Nusselt numbers and mass flow ratio are found to depend mainly on α, Pr and Ao.
Abstract: An analytical investigation of evaporation of laminar falling liquid film along an inclined wall is presented in this paper. The results for temperature distribution, local heat and mass Nusselt numbers and mass flow ratio are found to depend mainly on α, Pr and Ao. The other physical parameters igg, β and K are found to have only a mild effect on the results.
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TL;DR: In this paper, the authors present results from the 1975 International Solar Energy Congress and Exposition (ILSCE) in Los Angeles, California, USA and present a survey of the literature in various fields of heat transfer during 1975.
20 citations
TL;DR: In this article, a finite-volume-based incompressible flow algorithm on Cartesian grid is presented for the simulation of evaporation phenomena in a falling liquid film under low wall superheat conditions.
Abstract: A finite-volume-based incompressible flow algorithm on Cartesian grid is presented for the simulation of evaporation phenomena in a falling liquid film under low wall superheat conditions. The model employs the PLIC–VOF method to capture the free surface evolution, and the continuum surface force (CSF) approximation to emulate the effects of interfacial tension. The phase change process is represented through a source term in the interfacial cells, which is evaluated from the normal temperature gradients on either side of the interface. In order to evaluate these discontinuous temperature gradients across the interface accurately, a simple and efficient ghost fluid method has been implemented, which properly takes into account the dynamic evolution of the interface. The overall numerical model, including the phase change algorithm, has been validated against standard benchmark analytical results. Finally, the model is used to simulate the evaporating flow of a 2-D laminar, developing film falling over an ...
8 citations
Additional excerpts
...A fully developed evaporating liquid film flowing along an inclined wall has been addressed by Murty and Sastri [2]....
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References
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TL;DR: In this paper, the authors studied the diffusion equation subject to a phase change at one boundary, provided simple boundary conditions of the first, second, or third kind are specified, and provided exact solutions regarding relative motion between the phases, ablating slabs, and growth of a vapor film.
Abstract: Publisher Summary The study of the diffusion equation subject to a phase change at one boundary is in a relatively satisfactory state, provided simple boundary conditions of the first, second, or third kind are specified. Mathematically interpreted, the interesting features of the problem arise from the nonlinearity, exhibited for all but a few particular boundary motions. This chapter illustrates solution of the equation for diffusion of heat, mass, or some other scalar quantity, subject to the existence of a free boundary. The chapter aims to find exact solutions regarding relative motion between the phases, ablating slabs, and growth of a vapor film. Analytic approximation methods and analog and digital computer solutions are discussed in details. Integral equation methods, variation methods, and boundary layer methods along with active and passive analog solutions and application of numerical schemes are appropriate for bringing clarity to heat conduction or diffusion with phase change. In the search of growth of small particles of a condensed phase, the quasi-steady-state theory is applied particularly where a condensed phase exists whose volume changes slowly with time. This is true, for example, in the sublimation of ice or the condensation of water vapor from air on liquid droplets. While focusing on active and passive analog solutions, freezing problems remain symmetric in one, two, and three dimensions, where the liquid is initially at the fusion temperature. The heat capacity of the solidified phase is taken into account. Thermal properties are considered to be temperature independent.
105 citations
TL;DR: In this article, the effect of a moving interface on gas-liquid mass transfer was investigated, where the control of the mass transfer is entirely within the gas phase and the control is distributed between the two phases.
Abstract: A theoretical investigation has been made of the effect of a moving interface upon gas-liquid mass transfer, where the control of the mass transfer is entirely within the gas phase and where the control is distributed between the two phases. An analytical model is proposed for laminar interphase mass transfer in infinite media. Computer solutions have been obtained for gas-liquid mass transfer in confined phases. A cocurrent moving interface increases mass transfer confficients over what they would be for the same flow rate without interfacial motion.
25 citations
TL;DR: In this article, a solution of the diffusion equation with a constant surface resistance is presented for a flow down an incline, and an exact solution is obtained in terms of the eigenfunctions for which ten eigenvalues are tabulated.
18 citations
"Evaporation of laminar falling liqu..." refers background or methods in this paper
...tion with a constant surface resistance was presented by Tamir and Taitel [ 4 ]....
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...from the exact solutions [ 4 ] are used for the formula-...
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TL;DR: In this article, the authors presented an analytical study which describes the laminar accelerating flow of a thin film along an inclined wall and found that the non-dimensional film thickness depends on two parameters (Fr/Re and ρu-ratio), the effect of the latter being more pronounced for larger values of the former.
16 citations
"Evaporation of laminar falling liqu..." refers background in this paper
...interface temperature and film thickness [ 6 ]....
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...discussed earlier by Murty and Sastri [ 6 ] are found...
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TL;DR: In this article, an analytical and experimental study was made of the evaporation from pure and saline water films flowing down a heated vertical surface at Reynolds numbers between 160 and 600.
Abstract: An analytical and experimental study was made of the evaporation from pure and saline water films flowing down a heated vertical surface at Reynolds numbers between 160 and 600. Visual observation showed free surface evaporation. Film continuity was poor for pure water, but good for saline water, because of the influence of temperature and salinity on surface tension gradients. Evaporation rates were predicted by (1) a constant-property boundary-layer type of laminar analysis; (2) the constant-property Dukler “eddy” treatment; and (3) a variable property laminar analysis that took into account the boiling point elevation due to salinity. The experimental evaporation rates could be correlated by dimensionless moduli arising out of the laminar analyses, but best quantitative agreement was found with the Dukler eddy treatment.
11 citations