2013 1(12)

THERMAL CONDUCTIVITY OF METAL MATERIALS IN CONDITIONS OF ACTION OF CENTRIFUGAL ACCELERATIONS AND FORCES

Lepeshkin A.R.

P.I.Baranova Central Institute of Aviation Motors (CIAM), Moscow, Russia

The investigation of the thermal conductivity of a metal materials in the field of action of the centrifugal accelerations and forces is important for aerospace engineering.

The material thermoconductivity of the blades and disks used in the calculation of the thermal state of parts of the turbine rotor. The turbine blades operate at centrifugal accelerations of 40000... 100000 m/s² (4000 ... 10000 g) and the thermal conductivity change in these conditions we can expect significant. In addition to acceleration the tension centrifugal force acts on rotary parts.

The investigations  of the thermoconductivity of materials at centrifugal accelerations and  tensile  forces have not been conducted previously.

In the investigations the developed original method of evaluation 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 by 2 and 3 times 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 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 under the influence of centrifugal accelerations. 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.

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