This thesis presents a simulation based study into using an axially waved surface on the pistons of an axial piston machine in order to study the effects of the waved structure on the properties of the lubricating gap. Two numerical models are used for this study: one which is capable of calculating the macro and micro motion of the piston within the cylinder bore along with pressure and velocity distributions within the lubricating gap, and the second capable of using the velocity data from the first in order to calculate the heat generation due to viscous dissipation. The end goal of the investigation is to study the behavior of the waved structure and to establish if a particular structure is able to reduce energy loss within the lubricating gap due to pressurized fluid leakage, torque loss due to viscous friction, and heat generation due to viscous dissipation. Nine different configurations of the waved structure were simulated with three different values of peak number as well as three different values of peak amplitude. Eight different operating conditions of the axial piston machine are simulated in both pumping and motoring mode to establish the behavior of the waved structure with a large range of conditions. Predicted results show that certain waved structure configurations reduce energy loss in all three areas considered at most of the operating conditions. In addition, an improved model was used to preliminarily explore the effects of a more accurate temperature field on the lubricating gap. Predicted results show similar trends with comparisons performed between the models used for this investigation.
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