Heat and mass transfer in condensation of water vapor from moist air

Results of an analysis of heat and mass transfer in condensation of vapor from moist air are presented. The computational model is based on the solution of integral relations of boundary-layer energy and diffusion using the analogy of heat- and mass-transfer processes. The effect of the temperature and concentration boundary conditions on the relation of the components of the heat flux on the wall is analyzed. Results of calculations are compared to available experimental data. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 71, No. 5, pp. 788–794, September–October, 1998.     

Influence of internal response on the critical conditions of heat and mass transfer of carbon particles

Critical conditions of heterogeneous ignition and extinction of solid and porous carbon particles are determined in a gaseous oxidizer with allowance for concurrent chemical reactions and heat losses due to radiation in relation to inside diffusion of the oxidizer. The influence of the internal response on high- and low-temperature heat and mass transfer processes and the conditions of their implementation is investigated. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 71, No. 5, pp. 880–886, September–October, 1998.     

Diffusion model of longitudinal agitation in heat and mass transfer processes. 3. Third-level problems

The paper is a continuation of reports [1, 2] on a diffusion model (DM) used for describing heat and mass transfer processes. A heat exchanger (mass exchanging apparatus) is examined with two flows moving in the DM mode or in a mode of one of the limiting cases of the DM: initial displacement (ID) or ideal agitation (IA). All possible combinations are found. The problems are divided into three levels of complexity of the combinations. Derivation of formulas and solutions for determining the carrying capacities of the heat exchanger (mass exchanging apparatus) are considered as applied to the problems of the third level. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 6, pp. 845–951, November–December, 1997.     

Use of integral boundary-layer theory for solving conjugate problems of heat transfer in channels of high-power plants

The solution of the conjugate problem of convective-conductive heat transfer in the channels of power plants is presented. The problem of convective heat transfer in the gas phase is solved by the integral theory of heat transfer. A one-dimensional problem of conductive heat transfer in the material of the wall is solved by the finite-difference method. Relative laws of heat and mass transfer and friction are obtained by numerical integration with respect to the boundary-layer thickness. The effect of the material and geometry of the wall on the level of problem “conjugation” is studied. Translated from Inzhenemo-Fizicheskii Zhurnal, Vol. 73, No. 1, pp. 131–137, January–February, 2000.     

Unsteady mass transfer of spherical particles

A one-dimensional problem on unsteady diffusion of a distributed substance through a conventional diffusion boundary layer is formulated and solved. Based on its solution relations are obtained for calculation of the instantaneous and mean mass transfer coefficients for the times corresponding to layer formation. A procedure is proposed for calculation of the mentioned coefficients using the known dimensionless relations derived for the steady process. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 6, pp. 930–935, November–December, 1997.     

Two-dimensional model of heat and mass transfer in the process of fractional crystallization on a band

A two-dimensional model of heat and mass transfer in the process of fractional crystallization on a band is proposed. Algorithms for calculating the concentration of an impurity in a melt have been developed and the impurity distributions in a diffusion layer have been obtained for the cases of linear-profile and wavy-profile crystals on the basis of numerical experiments. It has been established that the impurity distribution is twodimensional in the case of a wavy-profile crystal. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 79, No. 3, pp. 30–36, May–June, 2006.     

Diffusion model of longitudinal agitation in heat and mass transfer processes. problems of the 2nd level

The paper is a continuation of [1] on systematization of the employment of a diffusion model (DM) for describing heat and mass transfer processes. The object of consideration is a heat exchanger (a mass exchanging apparatus) with two flows moving in the DM regime, ideal displacement, and ideal agitation. All possible combinations of them are found. The problems are distributed according to three levels of complexity. The solution of problems of the 2nd level is considered. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 5, pp. 724–733, September-October, 1997.     

Heat and Mass Transfer under Cooling of Flowing Water Sheets by an Air Counterflow

On the basis of the system of differential equations in partial derivatives, the boundary-value problem of heat and mass transfer under cooling of flowing water sheets by a turbulent air counterflow has been formulated. Its approximate analytical solution is given. From the point of view of the accepted model of interaction of flows, it has been shown that the obtained theoretical values of the heat and mass transfer coefficients are in good agreement with the experiment. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 78, No. 4, pp. 27–36, July–August, 2005.     

Determination of the local parameters of heat- and mass transfer in deep cooling in a tube bundle of fuel combustion products of thermal power plants

The specific features of heat and mass transfer of flue gases deeply cooled below the dew point of the steam contained in them have been analyzed. A method of determining the local parameters of heat and mass transfer in surface condensation heat utilization units is suggested. An analysis of the local characteristics of cooled and condensing combustion products allows one to study the relationship between the heat and mass transfer parameters and justify the optimum geometric characteristics of condensation heat utilization units. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 2, pp. 289–295, March–April, 2009.     

Modeling of radiative heat transfer and mass transfer processes in drop-flow-based heat exchangers for spacecraft

Modeling of radiative heat transfer and mass transfer in drop-flow-based heat exchangers for spacecraft is considered. A Monte Carlo-based numerical model is presented. Results obtained with the aid of the model are analyzed and compared with existing data. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 71, No. 1, pp. 92–96, January–February, 1998.     

Unsteady wave flows of a gas suspension with account for phase changes

A system of equations of unsteady motion of a gas suspension with account for heat and mass transfer is presented. As a result of the computational experiment, the effect of the gas vibrations at the channel inlet on the motion of the gas suspension and the rate of heat and mass transfer is studied. Specifically, it is shown that, in the considered parametric region, the gas vibrations enhance the interphase heat and mass transfer. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 73, No. 3, pp. 487–492, May–June, 2000.     

Wave motion of porous particles in a pulsating gas flow in the presence of heat and mass transfer with deepening of the evaporation zone

Based on numerical solution of the dynamics equations of a monodisperse gas suspension with allowance for the interphase forces of aerodynamic drag, virtual masses, and the forces caused by nonstationary effects around particles, the influence of different forms of low-frequency harmonic and anharmonic oscillations of the gas on the motion of porous particles in the presence of heat and mass transfer accompanied by deepening of the evaporation zone has been investigated. The dependences of the solid-phase motion, kinetics of evaporation-zone deepening, and heat and mass transfer on the parameters of gas oscillations have been established. It is shown that on removal of free moisture, oscillations at certain parameters lead to enhancement of interphase heat and mass transfer. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 5, pp. 11–19, September–October 2006.     

Some features of the heat and mass transfer in a fire within an atrium

A field method of calculating the heat and mass transfer in a fire within an atrium is proposed. Results of numerical simulation of the three-dimensional temperature, velocity, smoke optical-density, and visibility fields in the gas medium in a fire within an atrium with the use of the mathematical model developed are presented. It is shown that the mechanisms of heat and mass transfer determined by the method proposed substantially change the modern views on the dynamics of the dangerous factors of a fire within an atrium and that the pattern of thermodynamics of the gas in a fire obtained with the indicated model cannot be obtained with integral and zonal models. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 79, No. 5, pp. 135–146, September–October, 2006.     

Structure of pulse dispersed jet upon change in its frequency characteristics

Intensities of heat and mass transfer for continuous and pulse spray in interaction with the vertical surface of a heat exchanger differ considerably from one another when the time-averaged spraying rate [1–6] is kept constant. This difference is determined by characteristic properties of gas-drop flows of continuous and pulse sprays and their interaction with the heat-exchanging surface. Results of experimental studies of basic hydrodynamic parameters of pulse drop flow are presented: velocity and drop size dispersions, spectral characteristics of the kinetic energy of the spray at various distances from the source, and influence of the gas concurrent flow on these parameters. A difference in the heat transfer is shown upon variation of the pulse drop flow parameters from the heat transfer at the stationary supply of spray.     

Influence of stefan flow on the characteristics of heterogeneous combustion of a carbon particle in air

The influence of Stefan flow and radiation-induced heat losses on the characteristics of stationary high-and low-temperature stable and critical regimes of heat and mass transfer of a carbon particle in air is analyzed. The investigations are sponsored by the International Fund “Vidrodzhennya” within the framework of the program ISSEP (contract No. K6V100). Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 1, pp. 146–152, January–February, 1997.     

Features of the Heat and Mass Transfer in a Fire Within a Building of Complex Geometry

A method of calculating the heat and mass transfer in a fire within a building of complex geometry is proposed. The results of calculation of the three-dimensional temperature, velocity, and visible-range fields in the gas medium of a fire simulated in the atrium, corridors, and floors of a building with the use of the mathematical model developed are presented. The method proposed allowed us to reveal regularities of the heat and mass transfer in a fire within the building considered that substantially differ from the existing views of the dynamics of the hazardous factors of a fire in such buildings. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 78, No. 3, pp. 22–29, May–June, 2005.     

Heat treatment of organic polymers in a flow of a gaseous heat carrier

Processes of heat and mass transfer are studied during heat treatment of organic polymers in a superheated-steam flow. Promising environmentally safe engineering processes of treatment of plant biomass, plastics, and rubber wastes that contain petroleum products of sludges and soils are described. Academic Scientific Complex “A. V. Luikov Heat and Mass Transfer Institute of the Academy of Sciences of Belarus,” Minsk. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 69, No. 6, pp. 1021–1025, November–December, 1966.     

Analytical methods of investigation of the thermal state of a region with a moving boundary under the conditions of nonstationary heat transfer to the external medium

An analytical method of solution of combined problems of nonstationary heat conduction for a region with a boundary moving according to a known law and with a time-variable coefficient of heat transfer is developed. The idea of splitting the kernel of the obtained generalization of a singular integral Fourier transform with respect to a space variable provides a basis for the method. Theoretical results are used in mathematical simulation of heat transfer processes in the region with a moving boundary under the conditions of nonstationary heat transfer to the external medium. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 73, No. 1, pp. 125–130, January–February, 2000.     

Features and efficiency of interphase heat and mass transfer with a pulsation organization of the process

It is shown that, with a low-frequency organization of transient interphase heat and mass transfer, its intensity is higher than in the case of a stationary organization. Algorithms for computation of the interface and the time of phase contact in jet mixing of mutually insoluble media are given. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 71, No. 2, pp. 317–322, March–April, 1998.     

Theoretical modeling of systems of combined thermal protection

Based on a numerical solution of conjugate boundary problems that describe the processes of heat and mass transfer in two systems of thermal protection of the radiation-evaporation type, the efficiencies of these systems are compared. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 73, No. 1, pp. 44–51, January–February, 2000.