Method of a regular regime for the determination of variable thermal coefficients

Abstract

The present work deals with the application of the theory and methods of a regular thermal regime in the case of cooling (heating) a body at variable thermal coefficients. It is shown that the description of a process by the regular regime formulae is possible and makes sense but in this case thermal coefficients determining the rate m are averaged in some temperature interval Δt . The value Δt increases with Bi and at mean Bi it approaches the value of the initial excessive temperature ▪ 0 . Therefore, the regular regime method is suitable for the determination of the variable heat capacity c p ( t) and the variable heat transfer coefficient α( ▪) at low Bi, but makes no sense for the determination of the variable thermal conductivity λ( t) at mean and high Bi. In the present work the method of variable coefficients is applied to investigating heat capacity of metals in a region of phase conversions of the second kind and heat transfer of a spherical specimen in various media and at various temperatures.