Showing papers by "Raymond Viskanta published in 1987"
Journal Article•
TL;DR: In this article, the effects of radiative transfer on combustion and flow properties were investigated in a preheated methane-air mixture, and the effect of radiation transfer on the fully coupled structure and mean properties were assessed for an industrial natural gas-fired furnace.
92 citations
TL;DR: In this paper, the effects of radiative transfer on combustion and flow properties were investigated in a preheated methane-air mixture, and the effect of radiation transfer on the fully coupled structure and mean properties were assessed for an industrial natural gas-fired furnace.
Abstract: Turbulence/radiation interaction is examined in order to provide better fundamental understanding of temporal aspects of radiative transfer in combustion systems. Two aspects of radiative transfer in a turbulent medium are considered in this paper. In the first, transfer of radiation along a path with turbulent concentration and temperature fluctuations is calculated for the time-mean irradiance at a combustion chamber wall due to random concentration of absorbing species and emission with Gaussian probability density functions. In the second, turbulence/radiation interaction and the effect of radiation transfer on the fully coupled structure and mean properties are assessed for an industrial natural gas-fired furnace. The results of calculations based on the approximate formulation utilized here show that the effects of turbulence/radiation interaction on combustion and flow properties is relatively small for a preheated methane-air mixture. The interaction is greater when the oxidant is cold and the flame is relatively long. 24 references.
86 citations
TL;DR: In this paper, the role of natural convection in the melting of pure tin from a specially designed heater that formed a vertical wall of a rectangular cavity has been studied experimentally.
Abstract: The role of natural convection daring melting of pure tin from a specially designed heater that formed a vertical wall of a rectangular cavity has been studied experimentally. Temperature and solid-liquid interface position were measured under carefully controlled conditions, and the evolution of the melting front and temperature in the liquid melt with time were followed. The experimental data show the effect of natural convection in the melt on the motion and shape of the interface as well as on the melting rate. In addition, the data are used to validate a numerical model developed previously
54 citations
TL;DR: In this paper, the effects of the cylinder surface temperature difference and the spacing between the cylinders have been examined to examine the effect of the melting shape and the solid/liquid interface motion on the phase-change material.
Abstract: Simultaneous melting and solidification of a phase-change material around two horizontal cylinders spaced vertically have been investigated experimentally. Experiments have been performed to examine the effects of the cylinder surface temperature difference and the spacing between the cylinders. The solid/liquid phase-change process has been clarified from observations of timewise variations in the solid/liquid interface, flow visualization, and measurement of temperature distributions in the phase-change material. The results show that the melt shape and the solid/liquid interface motion are very sensitive to the surface temperature of the lower cylinder and the spacing between the cylinders
8 citations