Identification of the thermophysical characteristics of materials

From a unified methodological standpoint, the coefficient of the inverse problem of determining the thermophysical characteristics of a material from temperature measurements at its depth in the approximation of a semi-infinite body, single-layer and two-layer (with a layer of an ideal conductor) plate of finite thickness has been solved. The proposed technique does not employ operations of the smoothing of experimental data and allows one to remove the restrictions on the choice of the heating regime of the specimen of the material and to expand the range of measurements by the Fourier number.     

Mechanical and thermophysical characteristics of materials in fracture

On the basis of aspects of thermodynamics and methods of the theory of dimensions in relative form for solids, relations have been obtained linking the change of the functions of state, i.e., enthalpy and relative volume, with the heat of melting and the work of fracture in single loading. The presented relations describe satisfactorily the conditions of failure in melting various chemical elements, their oxides, nitrides, salts, as well as in single loading of various structural materials in a wide range of temperature changes.Institute of Strength Problems of the Academy of Sciences of the Ukrainian SSR. Translated from Problemy Prochnosti, No. 9, pp. 22–27, September, 1989.     

Simultaneous determination of thermophysical characteristics of materials

Nonstationary methods for the simultaneous experimental determination of the diffusivity and thermal conductivity of a semi-infinite body and a system of cylinders are analyzed.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 25, No. 5, pp. 851–858, November, 1973.     

Classification and database of thermophysical characteristics of heat protective materials

Classification and identification marking of heat protective materials and a database of their thermophysical characteristics are developed. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 73, No. 1, pp. 39–43, January–February, 2000.     

Determination of the temperature dependence of thermophysical characteristics of solid materials

A method is proposed to determine the thermophysical characteristics of solid materials on the basis of solving third- and fourth-order linear heat-conduction equations. It is shown that linear heat-conduction equations of order greater than two possess a high degree of accuracy of the solution.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 29, No. 1, pp. 91–94, July, 1975.     

Competing reactions in condensed phase combustion: wave structure and stability

We consider the use of step functions to model Arrhenius reaction terms for traveling wave solutions to combustion problems involving condensed-phase competing reactions such as those occurring in combustion synthesis via the self-propagating high-temperature synthesis process. For each reaction, the Arrhenius temperature dependence of the reaction rate is replaced by a step function. The resulting model introduces interior interfaces and allows the transport equations for energy and species to be solved explicitly within the subdomains bounded by these interfaces. The problem can then be reduced to a small number of algebraic equations describing appropriate interface conditions. We apply this methodology to study steady traveling waves with competing reactions, finding regions where multiple solutions are possible, and comparing our results with numerical calculations employing Arrhenius kinetics. We then analyze and determine regions of stability and instability for the traveling wave solutions.     

The frequency-pulse method for determining the thermophysical characteristics of solid materials

On the basis of a linear instantaneous heat source, we consider the frequency-pulse method of determining the thermophysical characteristics of solid materials without destruction of their integrity. We present the results for the investigation of the procedural error in the determination of thermophysical coefficients by the method of numerical simulation, as well as the results of experimental investigations. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 71, No. 2, pp. 336–341, March–April, 1998.     

Determination of the error in measurements of thermophysical characteristics of heat-insulating materials

A method of combined determination of thermophysical characteristics (TPC) of heat-insulating materials that is based on solving the inverse heat-conduction problem is discussed. The influence of the parameters of the calculation algorithm and the uncertainty in specifying the parameters of the measuring device on the TPC measurement error is analyzed. It is shown that the measurement error considerably exceeds the scatter of the results of repeated measurements of the same sample without disassembling the measuring device. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 71, No. 1, pp. 106–111, January–February, 1998.     

Quasilinear method for a joint determination of the thermophysical characteristics of materials

A method is described for jointly determining the thermophysical characteristics of materials. The method exploits certain features in the development of the initial stage of a regular regime.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 29, No. 3, pp. 436–440, September, 1975.     

Nondestructive techniques for determining the thermophysical characteristics of materials by the instantaneous-heat-source method

Using the method of a linear instantaneous heal source, we consider nondestructive techniques for determining the thermophysical characteristics of materials. A procedure for estimating errors in the techniques suggested is given. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 6, pp. 888–894, November–December, 1997.     

Method and installation for complex determination of the thermophysical characteristics of nonmetallic sheet materials

We present the theory behind the method of complex determination of the thermophysical characteristics, based on solution of the heat-conduction problem for a flat bicalorimeter under conditions of a regular thermal regime of the 2nd kind.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 16, No. 3, pp. 516–520, March, 1969.     

Determination of thermophysical characteristics of high heat-conductance materials on thin samples

A method is proposed that makes it possible to eliminate the contact thermal resistances in the determination of the thermophysical characteristics of high heat conductance materials on samples with thickness h5 · 10^–3 m.Translated from Inzhenerno-Fizicheskii Zhurnal Vol. 29, No. 6, pp. 1049–1056, December, 1975.     

Mathematical modeling of high-temperature thermophysical characteristics of rubber-like thermal protection materials

Based on analyzing and generalizing results of theoretical and experimental investigations of main regularities of heat transfer in the thermal protection of the combustion chamber, the mathematical and computer models of high-temperature characteristics of rubber-like thermal protection materials are formulated. The distinctive feature of the models is taking into account the change in the composition and structure of the destructing material in the process of heating up to high temperatures. Results of the numerical simulation satisfactorily agree with experimental data.     

Integrated determination of thermophysical characteristics of solid and granular materials at room temperature

A method is described for the integrated determination of the thermophysical characteristics of solid and granular materials at room temperature.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 16, No. 1, pp. 95–100, January, 1969.     

Determination of thermophysical properties of materials with the help of characteristics of imaginary frequencies

An effective method has been developed to determine thermophysical properties of materials from the available thermophysical measurements.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 61, No. 1, pp. 141–145, July, 1991.     

Determination of the thermophysical characteristics of materials by L. A. Semenov's Method

The first and fifth variations proposed by L. A. Somenov are discussed, for determining the thermophysical characteristics of materials under quasi steady-state conditions. An improved calculation procedure by these alternatives is proposed and data are presented which have been obtained from tests using this procedure.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol.20, No. 1, pp. 82–86, January, 1971.