Finite Element Analysis of a Hydraulic Engine Mount Including Fluid-Solid Interaction

Abstract Engine vibrations and noise are demanding issues in automotive industry from long times ago up until nowadays. These vibrations could be derived from rotating components, structural resonances, or combustion forces, which could potentially lead to discomfort, efficiency loss, and structural fatigue. For those reasons, vibration isolation devices have been developed to minimize these effects, such as Rubber Engine Mounts (REM), Hydraulic Engine Mounts (HEM), Active Engine Mounts (AEM), or Blance Shafts and Harmonic Dampers. This paper selects Hydraulic Engine Mounts (HEM) as the objective of study due to their remarkable damping characteristics and broad frequency effectiveness. To be more specific, traditional rubber mounts are useful for high-frequency vibration isolation but struggle with low-frequency engine operation. With the fluid damping mechanism, the HEM provides effective isolation over a broader spectrum of vibrations in both low-frequency and high-frequency conditions. On the other side, the Active Engine Mounts (AEM) bring out superior real-time vibration control, but they require sensors and electronic control units, raising up the cost and complexity of the system. According to these given drawbacks, the HEMs come out as the most advantageous solution due to their cost-effectiveness, complexity, and performance. Hydraulic Engine Mounts (HEM) are extensively used in automotive powertrains for effective vibration isolation and noise reduction, playing an important role as an energy-absorbing element, thus increasing the customers’ assuagement. The Hydraulic Engine Mount is composed of a double-chambers, an inertia track, a decoupler, and a plunger. As an energy-absorbing element, the HEM is anticipated to provide applicable frequency response characteristics under different operating conditions. Traditionally, a lumped parameter mechanical model is utilized for modeling the dynamic characteristics of HEM based on an analogy between electrical systems and mechanicalhydraulic systems, in which the system parameters are usually obtained by experiments. In this paper, a fluid-structure interaction 1(FSI) finite element analysis (FEA) and transient structural modules of ANSYS would be used to model and simulate the Hydraulic Engine Mount. The model is used to study the mechanism of Hydraulic Engine Mount and analyze key parameters of the mount for the effectiveness of vibration reduction. A CAD model of the HEM is built in Autodesk Inventor with a proper volume of the fluid in the mount with appropriate boundary conditions. Further, the model will be imported into ANSYS with fluid-solid interaction and transient structural modules to study fluid flow and understand dynamic mechanisms. The challenges in this study are to properly modify the volume of the fluid in the model to import to ANSYS Fluent Module and to set up the dynamic input boundary conditions in ANSYS Transient Structural Module before pairing these two modules in the System Coupling Module.