| A novel Fluid Structure Interaction (FSI) model of lateral lubricating gaps in External Gear Machines (EGM) is presented in this study. Modeling effort is directed toward improvement of the performance of the lubricating interface in EGMs in terms of power losses associated with this internal lubricating gap flow during the operation of this particular kind of positive displacement machine. This is achieved by modeling the phenomena involved with this lubricating gap flow, with particular focus on accurate prediction of lubricating film gap heights, pressures and viscous and volumetric losses arising from the lubricating interface. The modeling approach towards achieving the aim of predicting the performance of the lubricating interface is discussed, with details such as generation of finite volume meshes, coupling with other related models, development of fluid, structural and thermo-elastic finite volume solvers and development of a fully coupled FSI-Thermal algorithm. Simulation results of the proposed FSI model for a reference case representative of the most common EGM design solution have been presented. In addition, two experimental validations for the FSI model are presented: using experimental lateral gap leakage measurements and capacitive film thickness measurements.;The FSI model has also been used to create and simulate novel design solutions of the lubricating interfaces in EGMs. Simulation results from several such solutions are discussed with certain designs showing markedly improved performance. The generality of the proposed FSI model is also demonstrated and it has been used to simulate and improve upon EGMs with non-standard configurations. Modeling approaches and experimental results for these designs are described.;The first such model of EGMs, the FSI model has large potential to drive the design of future EGMs with improved efficiency and reliability, with low losses as well as low chances of wear. |
