Liquid sloshing is a common industrial problem affecting not only the dynamics of flow inside the container, but also of the downstream systems being fed from the container. This paper deals with the application of Computational Fluid Dynamics (CFD) for analyzing the possible effect of oil sloshing in compressors used in underground rail application on the continuous supply of lubricant to the pump to maintain a good lubrication of the system. Results are presented of a study done to track the oil/refrigerant interface near the inlet tube for some extreme conditions of acceleration, deceleration and track inclination. The study not only helped assess operating condition limits, but the calculated details of the oil motion also provided guidance for design modification for reducing sloshing. It further demonstrated the usefulness of CFD for design, analysis and operation of Positive Displacement Compressors.