IDENTIFICATION OF THE CHARACTERISTICS OF THERMAL ENGINEERING MATERIALS UNDER CONDITIONS OF NONSTATIONARY HEATING WITH CHANGES IN PRESSURE BY SOLVING INVERSE HEAT EXCHANGE PROBLEMS. 1. DEVELOPMENT OF COMPUTING ALGORITHMS

Modern space technology is characterized by structures that operate under conditions of intense, often extreme, thermal infl uences. The general trend in the development of technology is associated with an increase in the number of critical heat-loaded technical objects with rougher conditions for their thermal loading with simultaneously increasing reliability and service life, reducing material consumption. For spacecraft, ensuring thermal conditions is one of the most important sections of design, determining the main design decisions. Characteristic features of modern heat-loaded structures of space technology are nonstationarity, nonlinearity, multidimensionality, and the conjugate nature of heat and mass transfer processes. These features limit the possibility of using many traditional computational-theoretical and experimental research methods. Highly porous thermal insulation materials with low thermal conductivity are widely used in the thermal protection designs of modern space technology objects. These materials typically have an open-pore structure. This leads to the fact that the thermophysical properties of these materials depend signifi cantly on the gas pressure of the medium in which heat-protective structures based on them operate. It can also be noted that as the ambient pressure increases, a more intense increase in the thermal conductivity coeffi cient is observed. The purpose of this work is to develop a complex of experimental and mathematical tools for a system of identifi cation of the properties of highly porous materials operating under conditions of not only changing thermal loads, but also of variable pressure
Modern space technology is characterized by structures that operate under conditions of intense, often extreme, thermal infl uences. The general trend in the development of technology is associated with an increase in the number of critical heat-loaded technical objects with rougher conditions for their thermal loading with simultaneously increasing reliability and service life, reducing material consumption. For spacecraft, ensuring thermal conditions is one of the most important sections of design, determining the main design decisions. Characteristic features of modern heat-loaded structures of space technology are nonstationarity, nonlinearity, multidimensionality, and the conjugate nature of heat and mass transfer processes. These features limit the possibility of using many traditional computational-theoretical and experimental research methods. Highly porous thermal insulation materials with low thermal conductivity are widely used in the thermal protection designs of modern space technology objects. These materials typically have an open-pore structure. This leads to the fact that the thermophysical properties of these materials depend signifi cantly on the gas pressure of the medium in which heat-protective structures based on them operate. It can also be noted that as the ambient pressure increases, a more intense increase in the thermal conductivity coeffi cient is observed. The purpose of this work is to develop a complex of experimental and mathematical tools for a system of identifi cation of the properties of highly porous materials operating under conditions of not only changing thermal loads, but also of variable pressure
Author:  S. A. Budnik, A. V. Nenarokomov, D. M. Titov, V. L. Reviznikov
Keywords:  highly porous materials, inverse heat transfer problems, iterative regularization method, processing of experimental measurements
Page:  1095