Showing papers in "International Journal of Heat and Mass Transfer in 1979"

TL;DR: In this paper, a dimensionless correlation for predicting heat transfer coefficients during film condensation inside pipes is presented, which has been verified by comparison with a wide variety of experimental data.

TL;DR: In this paper, a closed description of the processes of intensive evaporation and condensation is obtained, based on which simple interpolation formulae are suggested, in the region of low-intensity processes.

TL;DR: In this article, the relationship between the turbulent Prandtl and Schmidt number is investigated and the results are based on modeled transport equations for the turbulent kinetic energy, the turbulent heat flux, and the turbulent mass flux.

TL;DR: In this paper, it is shown that the fully developed turbulent boundary layer must be treated in two parts: an outer region consisting of most of the boundary layer and an inner region in which the mean convection terms are negligible.

TL;DR: In this paper, a model of the two-phase turbulent jet is presented and a set of model differential equations is developed for cases in which the mean velocities of the phases are sensibly equal.

TL;DR: In this paper, the effect of buoyancy forces on the steady, laminar, plane flow over a horizontal plate is investigated within the framework of a first-order boundary layer theory, taking into account the hydrostatic pressure variation normal to the plate.

TL;DR: In this article, heat conduction in a chopped-fiber reinforced polyester resin during compression molding of thin sheet-like parts was investigated. But the authors focused on the deformation field and formulated a boundary value problem for the temperature distribution in the deforming SMC in terms of coordinates that move with the material.

TL;DR: In this paper, a numerical method to determine the heat transfer and phase change processes of a spherical particle in a jet stream is deduced, where variations of the thermophysical properties of the particle and of the plasma with temperature are taken into account.

TL;DR: In this paper, the results of an analytical investigation of natural convection in porous media completely enclosed by concentric spheres and horizontal cylinders have been reported, showing that a maximum value of the heat transfer occurs for the spherical and cylindrical geometries dependent solely upon the radius ratio for each geometry.

TL;DR: In this article, a selection of methods which are potentially suitable for practical drop size measurement are presented with particular attention to their difficulty and sources of error, and it is shown that selection of a method for a specific use poses certain questions, namely; 1) Is a mean or a distribution required? 2. What type of mean or distribution (spatial/temporal) is sought? 3.

TL;DR: In this article, a non-equilibrium irreversible thermodynamics, macroscopic laws of conservation, and the liquid-vapor equilibrium of a porous system are used to describe the history of moisture migration in porous media.

TL;DR: In this paper, the effect of slip velocity at a membrane surface is studied in detail for a tubular membrane system, and a second-order perturbation solution of the equations of motion is found to be very satisfactory.

TL;DR: In this paper, a model for the solidification of a dilute alloy is described, in which the equations of heat and mass transfer are coupled through the conditions at the moving phase boundary.

TL;DR: In this paper, the performance of the two types of segmented-plate arrays with each other and with the parallel-plate channel was compared. And the results depend on only a single dimensionless parameter which encompasses the relevant geometrical and fluid flow quantities.

TL;DR: In this article, an electrochemical analogue technique has been used to measure the mass-heat transfer distribution in pipes roughened with square small ribs, and it has been found that the mass transfer distributions are less non-uniform at higher Reynolds numbers and that they are virtually independent of the Schmidt number over a wide range of Sc.

TL;DR: In this paper, mass transfer at a vertical gas sparged electrode with and without superimposed electrolyte flow has been investigated and the results can be represented by an analogous correlation in which the Grashof number, characteristic for free convection, is replaced by a modified Archimedes number: Sh = 0.19(Sc.Ar ∗ ) 1 3.

TL;DR: In this article, the authors proposed a curve for film condensation of vapour in the absence of an appreciable external friction on the gas-liquid interface, which clearly reveals the region of laminar-wave motion, an extensive region of quasi-similar heat transfer and the fully developed turbulent heat transfer.

TL;DR: In this article, two phase natural convection adjacent to a heated, vertical surface in a permeable medium is treated using boundary-layer approximations for conditions under which the vapor layer adjacent to the heated surface is thin.

TL;DR: In this article, a set of governing differential equations is developed for simultaneous heat and mass transfer during the pendular state of drying, based on mass and energy transfer processes and on the liquid-vapor equilibria.

TL;DR: In this paper, the authors proposed a new method for thermal insulation system optimization based on minimizing thermodynamic irreversibility, which consists of externally controlling the variation of heat leak with temperature across the insulation.

TL;DR: In this article, the transient solution of two-phase, two-component flow in one-dimensional or axi-symmetric porous concrete structures exposed to time-dependent nonlinear mixed boundary conditions has been obtained.

TL;DR: In this article, the onset of convection in a horizontal water layer with regard to the density anomaly (near 4°C) was studied using linear stability analysis, and the resulting perturbation equations were solved with the aid of Galerkin's method.

TL;DR: In this article, the effects of free stream turbulence and velocity gradient on film cooling effectiveness were analyzed via line sink models and correlations based on an energy balance, the latter was much more successful in describing the film cooling measurements.

TL;DR: The flame zone model proposed by Libby and Economos is shown to be based upon the assumption of a one-step reversible chemical reaction with a large activation energy, and the limit of large activation energies is exploited by the method of matched asymptotic expansions as mentioned in this paper.

TL;DR: In this article, the authors present a second-moment approximation to turbulent convection in which the turbulent heat fluxes themselves form the subject of a set of transport equations Closure at this level avoids the need to prescribe the turbulent Prandtl number which is the principal empirical uncertainty in simpler treatments.

TL;DR: In this paper, an analysis of heat transfer in the post dryout region of upflow in a uniformly heated tube was performed on the basis of the three path heat transfer model, involving heat-transfer processes from wall to vapor, from vapor to liquid droplets and from wall-to-surface droplets in contact with the wall.

TL;DR: In this paper, a laminar flow with fully developed velocity profile is assumed to exist in a circular pipe or rectangular channel with constant wall temperature, and analytical expressions for the zero-, first-and second-order terms in the power series expansion of temperature are derived for the flow of a power law fluid.