Steady‐state estimation of thermal contact conductance between sliding disk and stationary cylinder with similar/dissimilar materials under the isothermally heated boundary condition

Abstract

AbstractAn accurate understanding of the thermal contact conductance (TCC) is imperative for the enhancement of the performance and service life of metallic cylindrical joints. However, the evaluation of the TCC between conforming cylindrical solids is quite intricate, as it depends on the temperature, pressure, roughness, relative sliding speed, and thermophysical properties of solids. Instead of generating contacting surfaces stochastically, in this communication, an experimental setup in the lab‐scale consisting of a stationary cylinder and a sliding hot disk has been fabricated in which temporal evolutions of the temperature on both solids are recorded by thermocouples. Effects of the disk temperature and relative sliding speed on the steady‐state TCC have been investigated. There is a cylindrical interface between two conforming smooth solids of similar/dissimilar materials. As there is the differential expansion of cylindrical solids due to the temperature gradient, the diameter of sliding disks has been truncated to fix the radial gap (contact pressure). Inverse solution with the conjugate gradient method along with the adjoint problem has been applied to estimate the steady‐state TCC. One‐dimensional heat transfer analysis shows that frictional heating is negligible. The steady‐state TCC is almost constant longitudinally along the axis of the steel cylinder. Under identical initial and isothermally heated boundary conditions, the TCC between the aluminum disk and cylinder is higher than that between steel disk and cylinder. Also, the TCC has been increased with a rising slope when the working temperature is enhanced. However, the augmentation of the relative sliding speed engenders a decreasing slope in the TCC graph.