SPACE-TIME REGION OF PROPAGATION OF HEAT FLUX THROUGH A LUBRICATED CONTACT WITH ACCOUNT FOR THE HEAT-SHIELDING EFFECT OF OIL FILMS

The investigations deal with the study of the heat-shielding effect of thin oil fi lms during the passage of heat fl ux through them, the conditions for its occurrence, and the space-time region of propagation through heterogeneous media with account for the reduced thermophysical characteristics. The paper presents theoretical calculations and experimental investigations conducted on a special self-engineered device. Consideration has been given to the infl uence of the oil fi lm thickness, the amplitude and time of the heat pulse on the velocity of its propagation simultaneously through a lubricated contact and an unlubricated one. The results of observations over the pattern of heat fl ux propagation has made it possible to draw a conclusion that the heat fl ux released, for example, as a result of friction on a microscopic contact is characterized by high density and propagates with a signifi cant velocity predominantly in the direction with the least thermal resistance determined by the thermophysical characteristics and the temperature potential of the material. Considering that the processes occur at the microscopic level, such materials include thin boundary fi lms (oil. oxide, spray-applied and other fi lms) with a thickness comparable with the height of microroughnesses.
   
Author:  D. A. Popov, A. M. Kadyrmetov, and A. S. Pustovalov
Keywords:  heat fl ux, boundary fi lms, heat-shielding effect, heat fl ux propagation
Page:  1456