Proceedings of SerbiaTrib '13

The results concluded for different grades ofKrytox at different values of clearance have beenattached at the end of the paper for referencepurpose however a summarized graph for both caseof thrust forces are plotted in MS Excel and areshown above.Based on the graphs attached at the end of thepaper and the summary graph displayed above,following is concluded:• The film varies almost linearly throughoutthe length of the tube. This can beexplained by the fact that during the slidingof one surface over the other the thrustforce increases and this increase in thethrust force causes an increase in thehydrodynamic pressure which is directlyproportional to the velocity of the slidingsurface. This increase in the hydrodynamicpressure requires an increased amount oflubricant to avoid metal-metal contact.• The small peaks in the beginning of thegraph can be explained with the help ofwobbling phenomenon that takes place dueto the impulsive nature of the forceprovided.• It is clear from the above graphs that thevalue of film thickness required, increaseswith increase in the viscosity of the liquidkeeping the clearance between the surfacesconstant. This conclusion is also supportedby the experimental results provided in theresearch carried out by Crook, A. W in1961 [15].• It is also concluded that with increase in theclearance between the surface the value offilm thickness increases this can also be13 th International Conference on Tribology – Serbiatrib’13 255