High Temperature 

About: High Temperature is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Heat transfer & Plasma. It has an ISSN identifier of 0018-151X. Over the lifetime, 3372 publications have been published receiving 18244 citations.

Fluid dynamics and thermal physics of two-phase flows: Problems and achievements

Abstract: The problem and specific aspects of studying two-phase flows laden with solid particles, droplets, and bubbles are considered. The main characteristics of two-phase flows and methods for their modeling are reported. The results of experimental and computation-theoretical investigations of two-phase flows of different types are described.

Solubility of Water in Supercritical Carbon Dioxide

Abstract: A new experimental circulation facility is developed to investigate the solubility of liquids in supercritical fluids at a pressure of up to 35 MPa and temperatures from 293 to 423 K. The solubility of water in supercritical carbon dioxide is experimentally investigated on the 313 and 323 K isotherms in the pressure range from 8 to 20 MPa. Empirical parameters of intermolecular interaction are obtained in the Soave approximation, which enables one to describe the solubility with an error that does not exceed the experimental error.

The Effect of Nonequilibrium Excitation on the Ignition of Hydrogen-Oxygen Mixtures

Abstract: The part played by various radicals and excited particles in reducing the induction period is discussed when analyzing the ignition of combustible mixtures under highly nonequilibrium conditions. A review is made of experimental and theoretical investigations of the effect made by atoms of hydrogen and oxygen, electron-excited molecules of O2(a 1Δg), and vibrationally excited molecules of H2 and O2 on the times of induction and on the shift of the limits of ignition of hydrogen-oxygen mixtures. The addition of atoms of oxygen and hydrogen to a combustible mixture may cause a significant reduction of the times of induction and the lowering of the temperature limit of ignition of combustible mixtures. However, the latter effect is observed only in the vicinity of the limit of ignition. In the zone of relatively low initial temperatures, the shift of the ignition limit is largely associated with the self-heating of mixture owing to recombination of atomic particles being added. In so doing, the nonequilibrium pattern of the impact hardly shows up. Molecules of singlet oxygen (SO) may be involved in both chain initiation reactions and chain branching reactions. The rates of these processes increase significantly with the temperature of the mixture. However, the temperature increase further causes an increase in the rate of reaction of hydrogen quenching of singlet oxygen O2(a 1Δg). The acceleration of deactivation of O2(a 1Δg) with increasing temperature, which was previously ignored by researchers, causes an abrupt reduction of the effectiveness of the impact of SO on the times of induction. In the low-temperature region, where the quenching is relatively weak, the effect of O2(a 1Δg) on the ignition of H2 : O2 mixtures may be significant in the case of a sufficiently high (in excess of 10−2) level of relative concentrations of SO. Vibrationally excited molecules of H2(v) may likewise be involved in chain initiation and branching reactions. The available results lead one to assume the possibility of lowering the temperature limit of ignition of hydrogen-oxygen mixtures in the case of intensive excitation of vibrational degrees of freedom of H2(v) molecules. However, in the case of electric-discharge excitation (even in H2 : O2 mixtures, in which a significant fraction of discharge energy may be delivered to the vibrational subsystem of H2(v)), it is quite difficult to attain high levels of vibrational excitation (T v H2 ≥ 2000 K). In a stoichiometric mixture of H2:air, where the bulk of discharge energy is spent for vibrational excitation of nitrogen molecules, this problem becomes even more complicated.

Liquid Gallium: Potential Uses as a Heat-Transfer Agent

Abstract: This paper deals with potential uses of gallium, as well as the most important gallium-based alloys, as energy carriers in high-safety nuclear power plants. Experimental data are given on the thermophysical, electrophysical, chemical, acoustic, and other properties of gallium and its alloys.

Numerical Simulation of Vortex Enhancement of Heat Transfer under Conditions of Turbulent Flow Past a Spherical Dimple on the Wall of a Narrow Channel

Abstract: Analysis is performed of studies into numerical simulation of a vortex flow and heat transfer in the vicinity of a dimple on a flat wall. To calculate the turbulent regime in a narrow channel with a spherical dimple on one of the walls, a multiblock algorithm for solving the Reynolds and energy equations is used which is based on structured partly overlapping grids and involves the use of the zonal k–ω model of shear stress transfer proposed by Menter. A tornado-like mechanism of enhancement of heat transfer in a spherical dimple of varying depth is analyzed in detail. Special attention is given to the rearrangement of the vortex structure and to a jumplike enhancement of heat transfer from wall with dimples.