Intensification of a Complex of Thermophysical Characteristics of a High-Enthalpy Thermally Decomposable Heat Protection on Joule Contact Heating Under High Vacuum Conditions

• Published in: Journal of engineering physics and thermophysics Vol. 98; no. 3; pp. 746 - 756
• Main Authors: Borshchev, N. O., Losev, M. I.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2025; Springer Nature B.V
• Subjects: Basis functions; Classical Mechanics; Complex Systems; Conjugate gradient method; Decomposition; Engineering; Engineering Thermodynamics; Enthalpy; Heat and Mass Transfer; Heat exchange; High vacuum; Industrial Chemistry/Chemical Engineering; Ohmic dissipation; Resistance heating; Temperature sensors; Thermal conductivity; Thermal protection; Thermodynamics; Thermophysical properties; Arrhenius equation; conjugate gradient method; iterative regularization method; Joule heating
• ISSN: 1062-0125; 1573-871X
• DOI: 10.1007/s10891-025-03154-7

A method of parametric identification of a set of thermophysical characteristics (specific thermal conductivity, specific heat capacity, integral reflectivity and emissivity) of high-enthalpy thermally decomposable thermal protection under Joule heating in diffusion approximation is proposed. The problem of finding the extremum of the mean-square functional of the residual between the theoretical and experimental temperature fields at the locations of temperature sensors is solved with preliminary specifications of the basis functions that take into account the dependence of the characteristics under consideration on temperature. Optimization of the thermal protection parameters is performed using the conjugate gradient method as the most accurate algorithm of the first order of convergence. For its implementation, three conjugate heat exchange problems are preliminarily solved to determine the sensitivity coefficients necessary to calculate the gradient of the residual functional under study.