Showing papers in "International Journal of Heat and Mass Transfer in 1988"

TL;DR: In this article, the combined effects of the rib angle-of-attack and the channel aspect ratio on the distributions of the local heat transfer coefficient for developing flow in short rectangular channels (L/D = 10 and 15) with a pair of opposite rib-roughened walls were determined for Reynolds numbers from 10 000 to 60 000.

TL;DR: In this paper, the authors investigated non-Darcian flow and heat transfer in high-porosity fibrous media and showed that the porous medium enhances heat transfer from a surface as compared to predicted results for slug or for laminar flow in a channel.

TL;DR: In this paper, the observed degree of thermodynamic imperfection of existing power plants is explained based on a steady-state power plant model the irreversibility of which is due to three sources: the hot-end heat exchanger, the cold-end and the heat leaking through the plant to the ambient.

TL;DR: In this paper, a volume averaged transport equation is used to model the phase change of a media with natural convection in the melt region, while phase change is assumed to occur over a small temperature range, and experiments are performed in a vertical, square enclosure using gallium and glass beads as the fluid and the porous matrix, respectively.

TL;DR: In this paper, the authors identify the most basic scales and regimes of the phenomenon of melting with natural convection in an enclosure heated from the side and show that the phenomenon consists of a sequence of four regimes: pure conduction regime, mixed regime, convection regime and shrinking solid regime.

TL;DR: In this article, the average incident radiations and the radiative heat fluxes are presented in graphical and tabular forms for two-dimensional rectangular enclosures using the S - N discrete ordinates method, where the medium is gray and absorbs, emits, and anisotropic scatters radiative energy.

TL;DR: The model of heat and mass transfer in porous media used in this article is deduced from Whitaker's theory and leads to a very comprehensive set of equations and takes into account the effect of the gaseous pressure.

TL;DR: In this article, a detailed hot-wire measurement of a turbulent natural convection boundary layer is made paying close attention to the characteristics of the near-wall region which has not been clarified quantitatively.

TL;DR: In this paper, the authors investigated pool boiling heat transfer in a confined narrow space for saturated water at atmospheric pressure between heated and unheated parallel rectangular plates, and they performed experiments at heat flux from boiling inception to the critical heat flux on heating surfaces with a width of 30 mm, lengths of 30 and 120 mm, and gap sizes of 5, 2, 0.6 and 0.15 mm.

TL;DR: In this paper, the dependence of active nucleation site density on boiling surface conditions is developed in a form of N = N · φ(β) · ε(r), where ϵ(n) is the average cavity density.

TL;DR: In this article, a detailed numerical analysis has been performed for a one-dimensional model of premixed combustion in a porous medium, and the effects of radiative heat transfer on the flame structure and burning velocity in gas-solid two-phase systems are clarified.

TL;DR: In this paper, the authors analyzed the impact Fourier number based on the maximum contact area radius and the contact duration is inversely proportional to the particle Peclet number and independent of mechanical properties.

TL;DR: The role of natural convection during solidification of a pure metal at a vertical wall is studied experimentally and numerically in this paper, where experiments are performed in a rectangular test cell with two opposing sidewalls helt at constant but different temperatures, while the remaining walls are well insulated.

TL;DR: In this article, a generalized correlation for forced convection vaporization heat transfer is suggested which is valid for both vertical and horizontal channels with a fully wetted perimeter, with a mean absolute deviation of 12.9%.

TL;DR: In this article, a mathematical model for turbulent two-phase flows is proposed to take into account the effects of both mean and turbulent motion of each phase on the other, and the modeled conservation equations are based on a Eulerian approach for the gas and a stochastic Lagrangian approach to the particles.

TL;DR: Forced convection heat transfer from an isolated cylinder in crossflow is investigated for Reynolds numbers up to 200 by direct numerical simulation of the Navier-Stokes and energy equations using the spectral element method as mentioned in this paper.

TL;DR: In this paper, a free-falling turbulent liquid film has been investigated experimentally and numerically and it exhibited a long thermal development length persisting up to more than one half of the 781 mm long heated test section.

TL;DR: In this paper, a numerical and experimental study for the case of two-dimensional buoyancy-driven convection in saturated horizontal packed beds is reported for weak dispersion and the effect of dispersion on Nusselt number is stronger than that of inertia unless the Prandtl number of the porous medium is of order 0.01 or less.

TL;DR: In this article, the reliability of Reynolds stress and turbulent heat flux measurements is verified by the excellent agreement with the indirect measurements estimated by integrating momentum and thermal energy equations with measured mean velocity and mean temperature.

TL;DR: In this article, the inner wall temperature is a function of diameter ratio and Rayleigh number, and a crescent-shaped eddy dominates for small diameter ratios and a kidney-shaped flow pattern appears for large diameter ratios.

TL;DR: In this article, the boundary layer solution predicting the heat transfer rate is derived on the basis of the numerical results, and it is shown that the Nusselt number is inversely proportional (1 + N) where N is the number of partitions.

TL;DR: Etude des effets des vibrations ultrasonores sur le transfert de chaleur par ebullition dans le cas du refrigerant R-113. Application possible au refroidissement par immersion des composants microelectroniques.

TL;DR: In this paper, the entire thermo-fluid-dynamic field resulting from the coupling of natural convection along and conduction inside a heated flat plate is studied by means of two expansions.

TL;DR: In this article, the notion of quadripole thermique is used to resoudre les transferts de chaleur unidirectionnels transitoires dans les systemes constitues de plusieurs milieux presentant a la fois des sources internes, des contacts imparfaits, des sources aux interfaces and des desequilibres de temperature initiaux.

TL;DR: In this paper, the authors investigated the thermal development of free-falling turbulent liquid films and found that the film flow exhibits rapid thermal development in the entrance region and enhanced heat transfer over the lower portion of the heated length, and a correlation of an averaged fully developed heat transfer coefficient is presented as a function of Reynolds and Prandtl numbers.

TL;DR: In this paper, steady-state natural convection of a saltwater solution due to the combined horizontal temperature and concentration gradients is studied experimentally in rectangular enclosures of aspect ratio, 0.2 and 2.0.

TL;DR: In this paper, Laminar natural convection flow next to a heated wall with single and repeated, two-dimensional, rectangular roughness elements is studied numerically and experimentally.

TL;DR: In this article, the heat transfer and pressure drop responses of a corrugated duct with rounded corners were determined numerically for a Prandtl number of 0.7, in the Reynolds number range from 100 to 1000, for three assigned corrugation angles and for four values of aspect ratios.

TL;DR: In this paper, the critical heat flux (CHF) for low flow of water in vertical annuli near atmospheric pressure (0.118 MPa) was measured and correlated according to the flow transition which occurred at CHF.

TL;DR: In this paper, the effect of small amounts of non-condensable gas on laminar film-wise condensation of a vapour-gas mixture flowing turbulently in a vertical tube was investigated.