Showing papers by "Ephraim M Sparrow published in 1985"
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TL;DR: In this article, the effect of interplate spacing on natural convection in an open-ended vertical channel bounded by an isothermal and an unheated wall was studied both experimentally and computationally.
126 citations
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TL;DR: Experiences de visualisation de l'ecoulement and du transfert de chaleur dans l'eau pour etudier l'effet de linclinaison θ sur la convection naturelle dans un canal a parois paralleles as mentioned in this paper.
Abstract: Experiences de visualisation de l'ecoulement et du transfert de chaleur dans l'eau pour etudier l'effet de l'inclinaison θ sur la convection naturelle dans un canal a parois paralleles. On fait varier l'ecartement adimensionnel entre les parois (S/H), le mode de chauffage, et la difference de temperature entre la paroi et l'air ambiant (nombre de Rayleigh Ra s ). Obtention d'une correlation entre Nu s , Ra s , S/H et θ
115 citations
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TL;DR: In this article, the combined-mode natural convection/radiation heat transfer characteristics of highly populated arrays of rod-like cylindrical fin arrays were evaluated and it was found that fin fin arrays are highly enhancing in terms of heat transfer.
Abstract: Experiments were performed to determine the combined-mode natural convection/radiation heat transfer characteristics of highly populated arrays of rodlike cylindrical fins (i.e., pin fins). The fins were oriented with their axes horizontal and were attached to a vertical heated baseplate. The investigated parameters included the number of fins in the array, the fin length and diameter, the baseplate-to-ambient temperature difference, and the presence or absence of adjacent shrouding surfaces. Finning was found to be highly enhancing (up to a sixfold increase in heat transfer), and even the longest fins were highly efficient. When the number of fins was increased for fixed values of the other parameters, the heat transfer increased at first, attained a maximum, and then decreased. Arrays having different diameter fins yielded about the same performance when the surface area of the fin-baseplate assembly was held fixed. Shrouding surfaces positioned close to the array decreased the rate of heat transfer. Calculations showed that the contribution of radiation was substantial and was greatest for more populous arrays, for longer fins, and at small temperature differences.
81 citations
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TL;DR: In this paper, heat transfer and pressure drop experiments were performed for cross-flow tube banks in which the individual tubes were equipped with longitudinal fins, and the results showed that a high degree of heat transfer enhancement can be obtained by finning, and enhancements for the various tube bank geometries were compared at fixed pumping power, fixed pressure drop, and fixed mass flow.
47 citations
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TL;DR: Mesure en soufflerie du coefficient de transfert de chaleur moyen et de la repartition radiale du coefficient DEF for un disque circulaire place dans un ecoulement normal uniforme pour des nombres de Reynolds allant de 5000 a 50000 as mentioned in this paper.
Abstract: Mesure en soufflerie du coefficient de transfert de chaleur moyen et de la repartition radiale du coefficient de transfert de chaleur pour un disque circulaire place dans un ecoulement normal uniforme pour des nombres de Reynolds allant de 5000 a 50000. Comparaison des valeurs experimentales du transfert de chaleur au point d'arret avec des previsions theoriques
45 citations
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TL;DR: In this article, experiments were performed to measure Nusselt numbers and pressure loss coefficients for annular-finned tubes deployed in either a one-row array or in an in-line or a staggered tworow array.
42 citations
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TL;DR: In this paper, the Nusselt and Rayleigh numbers were used to compare the data for the cube, the sphere, and the short vertical cylinder (height = diameter), all bodies of unity aspect ratio, and a new characteristic length was formulated.
39 citations
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19 citations
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TL;DR: In this paper, the passage average and local heat transfer coefficients and overall pressure drops were measured for both laminar and turbulent flow in a rectangular passage open along its lateral edges and closed at its downstream end.
17 citations
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TL;DR: In this article, a one-dimensional, radial heat flow model for a fluid-carrying, insulated horizontal cylinder which loses heat to air by natural convection was analyzed by solving the differential form of the conservation laws.
14 citations
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TL;DR: In this article, measurements were made to determine quasi-local heat transfer coefficients at the smooth principal wall of a flat rectangular duct whose other principal wall is covered by an array of blocklike elements (to be termed modules).
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TL;DR: In this article, mass transfer coefficients for shell-and-tube heat exchanger were determined from mass transfer measurements using the naphthalene sublimation technique, where the external surface of the tubes is coated with a film of naphalene, which sublimes when exposed to an air flow.
Abstract: Experiments are described in which shell-side heat transfer coefficients for a shell-and-tube heat exchanger were determined from mass transfer measurements. The mass transfer experiments were carried out using the naphthalene sublimation technique. In utilizing the technique, the external surface of the tubes is coated with a film of naphthalene, which sublimes when exposed to an air flow. Mass transfer coefficients were measured for fully developed flow conditions at each of the tubes in the cross section. These coefficients were transformed to heat transfer coefficients by employing the analogy between heat and mass transfer. Detailed pressure drop measurements were made internal to the heat exchanger, and the axial pressure distribution indicated that the fluid flow was fully developed downstream of the first compartment. The cross-sectionally averaged mass (heat) transfer coefficients and the pressure drop were compared with the predictions from two well-established methods for the thermal-h...
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TL;DR: In this article, the evaporation of a volatile liquid from a slot-like cavity situated in the lower wall of a flat rectangular duct was studied both numerically and experimentally for laminar, fully developed airflow in the duct.
Abstract: The evaporation of a volatile liquid from a slot-like cavity situated in the lower wall of a flat rectangular duct was studied both numerically and experimentally for laminar, fully developed airflow in the duct. The capillarity-induced curvature of the liquid surface was determined analytically and was found to be well represented by a circular arc. Owing to the surface curvature, the solution domain was partially rectangular and partially cylindrical. Interlocking and overlapping rectangular and cylindrical finite-difference grids were used for the numerical work, and the resulting evaporation rates agreed to within 0-3% with the experimental data, depending on the distance between the top of the cavity and the liquid surface. This excellent level of agreement demonstrates that for problems which do not fit neatly into a single coordinate system, highly accurate results can be obtained without having to resort to complex numerical methods. Supplementary numerical work demonstrated that the duct flow ups...
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TL;DR: In this paper, the coefficients de transfert de chaleur par tubes and des pertes de charge par compartiment and entre compartiments sur le cote calandre d'un echangeur de chalur a faisceau et calandre.
Abstract: Mesure des coefficients de transfert de chaleur par tubes et des pertes de charge par compartiment et entre compartiment sur le cote calandre d'un echangeur de chaleur a faisceau et calandre. Etude de l'influence sur des caracteristiques de la dimension des fenetres de chicanes et du nombre de Reynolds
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TL;DR: In this paper, an experimentale experimentale de the congelation d'un milieu a changement de phase dans a capsule cylindrique scellee en rotation.
Abstract: Etude experimentale de la congelation d'un milieu a changement de phase dans une capsule cylindrique scellee en rotation. Etude de l'effet de la rotation en fonction du taux de remplissage de la capsule et de l'axe de rotation (colineaire a l'axe de la capsule ou perpendiculaire). Etude de l'effet d'une surchauffe prealable
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TL;DR: In this article, the average and local heat transfer at the base surface of a cylindrical cavity whose opening is perpendicular to an oncoming freestream have been determined experimentally.
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TL;DR: In this article, the heat transfer characteristics for rotationinduced flow in a radial passage in a shaft rotating about its own axis have been investigated, where the passage was either centered in the shaft or was offset such that the respective ends protruded different distances from the shaft surface.
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TL;DR: Etablissement d'equations donnant les transferts de chaleur and les pertes de charge d'une rangee de tubes a ailettes and de 2 rangees de tubesa ailes alignes en quinconce en ecoulement croise.