Technique of studying thermal diffusivity of metallics in different directions in a field of centrifugal accelerations and forces

Abstract

Study of the thermal diffusivity of metallics in a field of centrifugal accelerations and forces is essential for aerospace engineering. Characteristics of thermal diffusivity of materials are used in calculations of thermal state of blades and disks of turbine rotors. An original technique and a device on semiconductors have been developed for determination of thermophysical characteristics of materials on an acceleration bench using a vacuum chamber, under centrifugal forces and accelerations. Presented are results on nonstationary heating of heat conductors in the radial and circumferential directions in a field of centrifugal forces and accelerations. Analysis of experimental results shows that the thermal diffusivity of heat conductors grows with rotational speed as compared with a static state without rotation. The thermal diffusivity phenomenon of concern has two components: from centrifugal acceleration and from centrifugal tensile load. From experimental data on the effect of tensile forces it follows that the second component is small. Thus, said thermal diffusivity growth is strongly associated with increase in the velocity of electron drift in ametal under centrifugal acceleration forces.