Heat and mass transfer in chemically reacting media with decrease in partial pressures of vapor

We present a mathematical model of heat and mass transfer in a chemically reacting medium-multi-component vapor-gas mixture system with decrease in partial pressures of vapor-gas components in a free reactor volume. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 73, No. 5, pp. 1012–1020, September–October, 2000.     

Convective heat and mass transfer of reacting particles at low Peclet numbers

The problem of convective diffusion to a spherical particle in a gas is solved under the condition that the surface chemical reaction rate depends on the reagent concentration near the surface.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 43, No. 1, pp. 131–134, July, 1982.     

Heat and mass transfer for turbulent flow of chemically reacting gas in eccentric annular channels

An algorithm is proposed for calculating the velocity, temperature, and concentration fields under conditions of cooling of a cylindrical heat-releasing rod, placed off-center in a circular casing pipe, by a longitudinal flow of chemically reacting gas [N₂O₄].Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 53, No. 2, pp. 186–191, August, 1987.     

Convective heat and mass transfer in the nonadiabatic evaporation of volatile liquids from a porous plate

This paper describes the apparatus, the experimental procedure, and the calculation of the characteristics of convective heat and mass transfer in the nonadiabatic evap oration of volatile liquids into a boundary layer from a flat porous plate situated longitudinally in a turbulent flow of air.     

Turbulence/shock wave interactions in chemically reacting flows

Physical interactions between turbulence and shock waves are very complex phenomena. If these interactions take place in chemically reacting flows, the degree of complexity increases dramatically. Examples of applications may be cited in the area of supersonic combustion, in which the controlled generation of turbulence and/or large scale vortices in the mixing and flame-holding zones is crucial for efficient combustion. Equally important, shock waves interacting with turbulence and chemical reactions affect the combustor flowfield resulting in enhanced relaxation and chemical reaction rates. Chemical reactions in turn contribute to dispersion of shock waves and reduction of turbulent kinetic energies. Computational schemes to address these physical phenomena must be capable of resolving various length and time scales. These scales are widely disparate and the most optimum approach is found in explicit/implicit adjustable schemes for the Navier-Stokes solver. This is accomplished by means of the generalized Taylor-Galerkin (gtg) finite element formulations. Adaptive meshes are used in order to assure efficiency and accuracy of solutions. Various benchmark problems are presented for illustration of the theory and applications. Geometries of ducted rockets, supersonic diffusers, flame holders, and hypersonic inlets are included. Merits of proposed schemes are demonstrated through these example problems. This research was supported by the US Army Missile Command (daah01-91-D-R002) and National Science Foundation (asc-8918081) and contributions were made by a number of graduate students, notably by W S Yoon.     

Nonisothermal flow of chemically reacting media with viscosity depending on temperature and pressure

The article investigates heat exchange and resistance when non-Newtonian, chemically reacting liquids, whose viscosity depends on the flow rate, the temperature, the pressure, and the degree of conversion, flow through flat pipes.     

Transport processes in a reacting boundary layer

An approximate calculation has been made for the boundary layer of a compressible gas in a laminar flow over a semi-infinite porous plate reacting with an injected substance in a homogeneous reaction at an infinite rate. The possibility of applying the solutions obtained to a turbulent boundary layer is also examined.     

Calculation of vibratory processes in liquids during heat transfer from hot channel walls

Vibration modes in liquids during heat transfer with phase transformations are classified here on the basis of generalized test data. Criterial equations of self-excitation and for the natural frequency of harmonic vibrations are derived analytically. These equations are in satisfactory agreement with test results.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 25, No. 2, pp. 217–226, August, 1973.     

A method of computing heat transfer coefficient in the flow of a chemically reacting N2O4 gas

A criterial relation is derived which connects the heat transfer coefficient with the difference in the concentrations of the O₂ component at the wall and in the flow. A method of determining the concentration difference is proposed. A comparison with the experimental data shows that the proposed method gives satisfactory results in a wide range of pressures and temperatures.     

Heat and mass transfer in a turbulent reacting flow in an annular channel (internal heat conductor). Part 1. Stabilized heat-transfer segment

Theoretical formulas are derived for the heat and mass transfer characteristics in a turbulent chemically nonequilibrium flow. The functions needed to derive the mean-mass values for the relative temperature and composition have been calculated throughout the range in the flow parameters, namely from quasifrozen to quasiequil:.brium, and the same applies to the Nusselt number at the inner surface and the relative adiabatic temperature on the stabilized heat-transfer part. Fitted expressions are derived for those functions, which give the major characteristics with errors of 3%.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 59, No. 5, pp. 729–736, May, 1990.     

Modeling the heat transfer when a chemically reacting flow passes a rib by means of the finite-element method

The finite-element method is used to solve the conjugate problem of heat transfer between a ribbed wall and a chemically reacting flow. The distribution of the velocities, temperatures, and concentrations, as well as the local heat-transfer coefficients and efficiency of the rib, is obtained.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 55, No. 2, pp. 202–208, August, 1988.     

Moisture transfer in a closed system with an internal heat source

The author examines moisture transfer between a solid containing an internal heat source and a liquid in a system closed in the moisture-transfer sense. The influence of the difference in sorption characteristics between solid and liquid on the redistribution of moisture is shown. Internal moisture transfer in high-voltage power transformers is considered as an example.     

Some problems in the thermodynamics of nonideal chemically reacting gas mixtures

A method has been developed for the exact and approximate calculation of the equilibrium composition and thermodynamic properties of mixtures of nonideal chemically reacting gases described by an equation of state in virial form. Certain characteristics of the thermodynamics of diatomic dissociating gases are analyzed.     

A continuum theory of chemically reacting mixtures of fluids and solids

In this work, a continuum theory of a chemically reacting mixture composed of solids and fluids is presented. Following a different line of localization, a set of balance equations applicable to every component in the mixture is obtained. These are: conservation of mass, balance of momenta, conservation of energy and the principle of entropy which is also given for every species in the mixture. The localization is so applied that the individual energy equations are form invariant under time dependent motions of the spatial frame of reference and every state variables appearing explicitly in these equations can be considered as objective quantities. By use of the concept of reactive mass density for solid continuum and modifying the axiom of equipresence, originally developed for single bodies, a set of thermodynamically admissible constitutive relations is derived for a reacting mixture composed of a solid and a non-Newtonian fluid. Finally, utilizing the linearized field and constitutive equations, the propagation of simple harmonic waves in such a medium is studied and several particular cases are discussed.     

The dispersion of a chemically reacting solute in a micropolar fluid

The paper presents solution for the dispersion of a solute in a micropolar fluid flow in a circular pipe in the presence of an irreversible first order chemical reaction. It is shown that the solute is dispersed relative to a plane moving with the mean speed of the flow with an effective Taylor dispersion coefficient, dependent on two parameters, κ/μ and λ characteristic of the micropolar fluid and also on the reaction rate parameter a for a homogeneous reaction in the bulk of the fluid in which the solute is dispersed. It is found that for a given the effective Taylor dispersion coefficient decreases with an increase in κ/μ for fixed λ while it increases with increase in λ for fixed κ/μ. It decreases with increase in a for assumed values of κ/μ and λ.     

Convective heat transfer in external flows

Research on convective heat transfer in single-phase external flows, carried out at the Institute of Physical and Technical Problems of Energetics of the Academy of Sciences of the Lithuanian SSR over a broad interval of Reynolds and Prandtl numbers, is described and the principal results are presented. Attention is focused on questions of heat transfer intensification.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 53, No. 5, pp. 725–733, November, 1987.