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Showing 1 to 20 of 23 for “"Falling film"”.
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Falling-film evaporation over horizontal rectangular tubes
The present study is the first investigation of falling-film evaporation over horizontal rectangular tubes. This geometry is representative of the external profile of microchannel tubes. Incorporating these designs into shell-and-tube heat exchangers has the potential to provide compact, …
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Heat transfer coefficients in a falling film condenser
Thesis: M.S., Massachusetts Institute of Technology, Department of Chemical Engineering, 1935
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Flow fields and heat transfer of liquid falling film on horizontal cylinders
A liquid film flowing over horizontal cylinders is of great importance as a high rate of heat transfer exists between the falling liquid film and the horizontal cylinders. The objective of this research is to use numerical predictions, following experimental verification, to study the flow field …
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The intertube falling-film modes: Transition, hysteresis, and effect on heat transfer
Horizontal-tube falling-film heat exchangers enjoy wide application because they offer superior thermal performance and operate with less fluid charge than conventional shell-and-tube or flooded heat exchangers. Recent developments vitiate the heuristic design approach of the past, and a clearer …
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Development and validation of a thermodynamic model for predicting mode transitions in falling film flows over horizontal tubes
Horizontal-tube, falling-film heat and mass exchangers are important to many industries, with example applications in thermal desalination, vapor compression machines, absorption chillers, and natural gas liquefaction. Falling-film heat and mass exchangers are attractive for these applications …
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The mitigation of crystallization fouling in a falling-film flow: A self-cleaning mechanism driven by flow and wetting behavior
… on both flat and horizontal tube surfaces under falling film flow conditions. An alternated hydrophilic-hydrophobic patterned surface has been designed to achieve spatial scale-controlling, which promotes nonuniform scale layer distribution, particularly a height step along the wettability …
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Experimental Study of Capillary-Assisted Solution Wetting And Heat Transfer Using A Micro-Scale, Porous-Layer Coating On Horizontal-Tube, Falling-Film Heat Exchanger
The horizontal-tube falling-film heat exchangers have many different applications ranging from large refrigeration systems to desalination due to their high heat transfer coefficients with low liquid inventory. However, the problem of partial solution wetting severely deteriorates the heat transfer …
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Experimental Study of Meniscus Thin-Film Evaporation in a Horizontal-Tube, Falling-Film Heat Exchanger, Focusing on Dynamic Contact Angle Variation of an Advancing Meniscus
… dynamics were studied with respect to thin-film evaporation, specifically focusing on a horizontal-tube, falling-film heat exchanger. Experiments were carried out investigating the effects of solution subcooling, evaporator wall superheat, and porous-layer coating on the portions of sensible …
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The experimental study and numerical simulation of falling liquid film flow on horizontal tubes
… report has been found so far in studies of water falling film up to 100 mm intertube spacing. No simulation analysis of film thickness under influence of intertube spacing in 3 dimensional models. Therefore, to the best of author’s knowledge, this research aims to illuminate the effects of …
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Modelling the behaviour of a stationary horizontal liquid jet impinging on a vertical wall
… the velocities measured by PIV. The Nusselt thin film assumption, generally used when the flow is laminar and uniform, was found to be inaccurate as the flow is wavy and unsteady. The modelling of the draining film zone was based on the work of Mertens et al. (2005). This model was found to …
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Performance evaluation of a mechanical vapour compression desalination system
… the simulation also provided information on film thickness, evaporation rate, heat transfer coefficients, concentration profile and temperature profile in the falling film evaporation process.
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Experimental Investigation and Validation of Boiling and Condensation Thermal Resistances in Cylindrical Thermosyphons and Screen-Wick Heat Pipes.
… screen-mesh wicks to quantify pool boiling, falling-film boiling, and condensation resistances. Experiments were performed over fill ratios of 0.35–0.75, aspect ratios of 5.3–12.5, inclination angles from 20° to 90°, and evaporator heat-input rates of 6.8–34.0 W. Based on the observed …
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Nonlinear long-wave interfacial stability of two-layer gas-liquid flow
… and capillarity, and reduces to the single-phase falling film Benney equation for sufficiently thin liquid films and constant gas density. The case of two incompressible fluids is investigated first. Since the experimental conditions for this effective system are unclear, we consider several ways …
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Mathematical modeling and design of novel semi-continuous and continuous crystallizations
… crystallization, layer crystallization, and falling film crystallization) and examining mass and heat transport, crystal growth, and impurity migration. The first study investigates a new process for crystal size distribution (CSD) control that combines antisolvent crystallization in a dual …
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Manufacture, Concentration, and Functionality of Micellar Casein Concentrate
… (MCC). The second part evaluates a wiped film evaporator (WFE) to concentrate MCC. The third part evaluates heat stability of the high concentration MCC produced by WFE. In part 1, the primary objective was to achieve >25% total solids (TS) without a loss of water removal rate associated …
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Spatio-Temporal Analysis of Flows Close to Free Water Surfaces
… are tested in several ways: A laminar falling film serves as reference flow. The predicted parabolic profile of this stationary flow can be reproduced very well. Buoyant convective turbulence acts as an example for an instationary inherently 3D flow. The direct estimation of the wall …
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Modeling the Transient Response of a Thermosyphon
… shear stress between the rising vapor and the falling film in the thermosyphon, the influence of the mass in the liquid pool in the evaporator, and by using a more refined and accurate numerical grid. Unique to this model was the accounting for temporal changes in the effective length of the …
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