Showing papers in "International Journal of Thermal Sciences in 1999"

TL;DR: In this article, the first results of a benchmark problem concerning the simulation of coupled natural convection and melting from an isothermal vertical wall are presented in detail and show that, while qualitative agreement is obtained in most situations, it is still relevant to proceed to thorough numerical comparisons before assessing the accuracy of the different algorithms.

TL;DR: In this paper, the authors proposed a simulation model to determine the optimum high pressure for different operating conditions as a function of the refrigerant temperature at the gas cooler outlet for transcritical CO2-systems with the main components compressor, gas cooler, expansion unit and evaporator.

TL;DR: In this article, the authors discuss current and forthcoming applications along with the respective appropriate technology for heat transformation with sorption systems, and the use of solar energy as heat source also belongs to this area.

TL;DR: In this article, the authors presented a theoretical analysis of a solar radial air heater, operating on natural laminar convection in steady state, to predict the thermo-hydrodynamic behavior of the device.

TL;DR: In this article, a model for the description of the entire fouling process has been established, which is influenced by the nucleation rate and the adhesive strength between crystals and heat transfer surfaces.

TL;DR: In this paper, the optimal configuration for a finned plate (with rectangular and vertical fins) to be cooled in natural convection was analyzed using a simplified relation of the fins heat exchange.

TL;DR: In this article, the results of simulations of natural circulation loop performance, obtained by Cathare and Relap codes, are reported and compared with experimental data gathered in the MTT-1 loop.

TL;DR: In this paper, an experimental flow visualisation study has been conducted using several techniques (smoke technique, oil and pigment and the thermotropic liquid crystal technique) to determine the flow pattern for a row and a system of jets impinging on a flat plate with subsonic velocity.

TL;DR: The constructal theory of the origin of geometrical form in natural flow (open) systems began with the discovery that, contrary to the established view, the tree network can be deduced from a single principle: the geometric minimization of resistance in volume-to-point flow.

TL;DR: In this paper, a module welded plate heat exchanger was developed for handling aggressive media, which can be disassembled and mechanically cleaned outside the modules, and the capacity can also be subsequently modified by changing the number of plates or the plate patterns can be altered as it can be with the gasketed units.

TL;DR: In this article, a general non-dimensional mathematical model of evaporative cooling devices is applied to cooling towers and a rating procedure of the overall performance of a cooling tower is simple and consists of the adjustment of the assumed straight air saturation line to the real air saturation data.

TL;DR: A comparative study between models with transfer function (two-port) and nodal models is carried out in a Laplace space and in a time domain, bringing to the fore the physical content of the transfer matrix.

TL;DR: In this article, the complete Navier-Stokes and energy conservation equations are solved for a steady, fully developed, incompressible laminar flow with constant physical properties in ducts with elliptic or rectangular cross section.

TL;DR: In this paper, the effect of the curvature, the buoyancy ratio, the Lewis number and the transpiration parameter on the local Nusselt number and local Sherwood number was analyzed using the implicit finite difference method as well as the local nonsimilarity method.

TL;DR: In this paper, a three-equation or three-temperature macroscopic model for describing heat transfer in a porous medium subject to a two-phase flow is presented.

TL;DR: In this article, a molecular dynamics simulation is performed to analyse the limits of macroscopic behaviour of an isolated evaporating liquid sodium droplet and the Lennard-Jones 12-6 potential is used to determine the intermolecular forces.

TL;DR: In this article, a preliminary study of the heat transfer rates in the boundary layer without blowing permits us to validate, comparing with experimental results, the RNG κ-ϵ model.

TL;DR: In this article, the effect of different productive structures on the results of the thermoeconomic analysis of a combined thermal power plant is analyzed. And the influence of these choices on the average costs of the products of different components and of the total system has been studied.

TL;DR: In this article, the authors proposed a new hybrid system of solar powered water heater and adsorption icemaker, which can be used in the same space and at the same time is attractive initiative to enhance the COP of a system.

TL;DR: In this paper, the photothermal camera is used for thin coatings characterisation and for crack detection, where a heat source and an infrared (IR) detector together scan the material surface to monitor the temperature rise induced by the moving heating spot.

TL;DR: In this article, the authors presented a numerical study of the two dimensional heat transfer through the hollow structures used in the construction of building envelopes, and compared the heat fluxes predicted for structures that differ by the number of alveolars.

TL;DR: In this paper, a Rayleigh-Ritz method is presented for the achievement of a reduced model for nonlinear thermal problems, which consists of "branch" eigenfunctions, originally used in mechanical problems.

TL;DR: In this paper, a scale-invariant statistical theory of fields is presented that leads to invariant definition of density, velocity, temperature, and pressure, suggesting that the Kelvin absolute temperature scale is equivalent to a length scale.

TL;DR: In this article, the convective heat transfer between the walls of an annular gap with a rotating inner cylinder is studied experimentally and numerically, where the surfaces of the cylinders are either smooth, or the moving wall is smooth and the other is axially grooved.

TL;DR: In this article, a simple change of dependent variables that guarantees positivity of turbulence variables in numerical simulation codes is proposed, which is valid for any numerical scheme be it a finite difference, a finite volume, or a finite element method.

TL;DR: In this paper, heat transfer in scraped-surface heat exchangers (SSHE) of processing turbulent flowing media has been numerically simulated using a two-equation κ - ϵ turbulence model.

TL;DR: In this paper, a study of the heat and mass transfer in a trapezoidal cavity heated from the bottom and cooled from the inclined upper wall is undertaken, where momentum, energy and concentration equations are computed by finite volumes method.

TL;DR: In this article, the problem of transient laminar forced convection within the thermal entrance region of parallel-plate chennels is analytically solved for by making use of GITT and mixed symbolic-numerical computation ( Mathematica 3.0 system).

TL;DR: In this article, the thermal behavior of two electric heating floor panels containing respectively water and n-octadecane paraffin in a concrete structure was examined and validated analytically and experimentally, which led to the choice of dimensions and operating characteristics for each panel.

TL;DR: In this paper, a thermal accumulator working on the effects of absorption and rejection of heat energy at the solid-liquid phase change of the heat storage substance is discussed, and a numerical method for calculating heat storage and the characteristics of heat storage devices is described.