Dynamical mechanisms of the temperature differences arising under uniform heat exchange conditions

Abstract

Analytical study of dynamical mechanisms of the temperature differences between the elements of truss constructions under uniform heat transfer conditions is completed. The time-dependent temperature differences are associated with the different thermal time constants of the truss elements. In this study the truss elements are assumed to be the rods with low Biot numbers that allow one to consider them as thermally-thin bodies. The conductive lengths of the rods are supposed to be much smaller than the corresponding dimensions that allow one to neglect the conductive heat transfer. Analytical evaluations of the temperature differences are made for the following stepwise changing and oscillatory operating parameters: the ambient temperature; the heat flux density on the elements surface; and the convective heat transfer coefficient. The temperature differences are shown to be small for the two operating conditions limits. Firstly, for the case when all the time constants of the elements are much larger than the period of the operating parameters oscillation. Secondly, for the case when the time constants of all the elements are much smaller than the period of the oscillations.