The increase of thermoconductivity of materials in the field of centrifugal accelerations and forces

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.

The investigation of the thermal conductivity in a materials under influence of the centrifugal accelerations and forces is a new work which is important for aerospace engineering. The material thermal conductivity of the blades and disks used in the calculation of the thermal state of parts of the turbine rotor. In the investigation the developed method of investigation of thermal conductivity of materials in the field of centrifugal acceleration and forces has been used. A device with a heat conductor to determine the thermophysics characteristics on the spin rig using the vacuum chamber in conditions of centrifugal acceleration and forces has been developed. The results of the investigations of unsteady heat-conductor in the field of centrifugal forces and accelerations are given. From the analysis of the results of experimental investigations it may be stated that the thermal conductivity of the heat-conductor increases significantly with an increase of a rotation frequency compared to the steady state without rotation. In the studied phenomenon of thermal conductivity the two components are present: the action of the centrifugal acceleration and centrifugal tensile load. The second component is a small value (10-20%) on the basis of obtained experimental data on the influence of stretching. Thus, this increase of the thermal conductivity significantly associated with an increase of an electronic conductivity (electron transport) of the metal due to heat-carriers (having mass) - free electrons under the influence of centrifugal accelerations taking into account Wiedemann-Franz law. The obtained results are of practical importance for the assessment of the thermal state of the rotating parts of aircraft engines and other energy turbomachines.