DETERMINATION OF COEFFICIENT OF FRICTION OF HYDRODYNAMIC JOURNAL BEARING EXPERIMENTALLY

Knowing friction coefficient is important for the determination of wear loss conditions at Journal bearings. Tribological events that influence wear & its variations effect experimental results. In this study, friction coefficient as  example at  radial bearings such as copper, brass hasbeen determined by a new approach .in experiment ,friction effect of bearing have been examined loads and velocities .The coefficient of friction ,often symbolized by greek letter  , is a dimensionless scalar value which describes the ratio of the forces of friction between  two bodies and the forces pressing them together . the coefficient of friction depends on the material used; for example ,ice on steel has a low coefficient of friction ,while rubber on pavement has a high coefficient of friction .coefficient of friction range near zero to greater than one.Vortex tube is considered as a mechanical device which operates as a refrigerating machine. This device separates a compressed gas stream into hot and cold streams. In this paper a series of experiments has been carried out to investigate the influence of uniform curvature of main tube on the performance of the vortex tube. The Ranque-Hilsch vortex tube has been used for many decades in various engineering applications.Because of its compact design and little maintenance requirements, it is very popular in heating and cooling processes. Despite its simple geometry, the mechanism that produces the temperature separation inside the tube is fairly complicated. A number of observations and theories have been explored by different investigators concerning this phenomenon. This report goes over some of the major conclusions found from experimental and numerical studies since the vortex tube's invention. One of these studies showed that acoustic streaming caused by vortex whistle plays a large part in the Ranque-Hilsch. In addition, thermal and kinetic energy considerations have been used to explain temperature separation