Master of Science (MS)


Mechanical Engineering

Document Type



An O-ring seal is of paramount importance in hydraulic and pneumatic machinery used in oil and gas drilling processes. O-ring seals are generally employed to contain the environments of working fluids existing on either side of the seal from interacting with each other, to maintain a uniform pressure chamber and to eliminate the environmental contaminants that interact at the rubbing interface. Failure of dynamic O-rings in hydraulic and pneumatic machinery often results in considerable productivity loss to the chemical and petrochemical industries. Therefore, it is highly important to determine the life of an O-ring for these applications under various operating conditions and to predict and prevent the possible O-ring seal failure. The purpose of this research was to design and build a new O-ring seal test rig (OSTR) capable of testing various O-rings. The O-rings were evaluated by considering effects of peripheral sliding velocity and operating differential pressure. This thesis contains both theoretical and experimental phases associated with the performance of the Buna-N O-ring seal with variations in peripheral sliding velocity and operating differential pressure. Experimental measurements of temperature, flow rates, differential pressures, shaft rotating speed, power loss, friction torque for corresponding tests were performed. Variations of frictional torque, O-ring power loss and interfacial temperatures with changes in sliding velocity and operating pressure differential are also presented. In order to analyze the temperature at the contact interface, a two-dimensional axisymmetric computational fluid dynamics (CFD) model is preprocessed in GAMBIT and thermal heat transfer analysis is carried out using a commercial CFD package, FLUENT. Results reveal that the O-ring friction power nearly linearly increases with increase in sliding velocity. Further, it is found that the friction power significantly increases with relatively higher pressure differentials. Friction torque is found to drop with increase in shaft speed and rises at relatively higher pressure differentials. Moreover, the interfacial temperatures are found to increase with increase in sliding speed and operating pressure differentials.



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Committee Chair

Khonsari, Michael M.