Study of Liquid Sloshing using a Multibody Approach

1Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 West Taylor Street, Chicago, IL 60607. 2Mechanical Engineering Department, Comillas Pontifical University, Madrid, 25‐28015, Spain 3Department of Astronautics Engineering, Harbin Institute and Technology, Harbin, Heilongjiang, 150001, China The objective of this investigation is to develop a total Lagrangian liquid sloshing solution procedure based on finite element floating frame reference (FFR) formulation and absolutely nodal coordinate formulation (ANCF). The proposed liquid sloshing modeling approach can be used to avoid the difficulties of integrating most of fluid dynamics formulations, which are based on the Eulerian approach, with multibody system dynamics formulations. The use of this approach allows for developing an inertia‐variant fluid model that accounts for the dynamic coupling between different modes of the fluid displacements. The FFR model is integrated with a MBS railroad vehicle model in which the rail/wheel interaction is formulated using a three‐dimensional elastic contact formulation that allows for the wheel/rail separation. Several simulation scenarios are used to examine the effect of the distributed liquid inertia on the motion of the railroad vehicle. The results, obtained using the sloshing model, are compared with the results obtained using a rigid body vehicle model. The comparative numerical study presented in this investigation shows that the effect of the sloshing tends to increase the possibility of wheel/rail separation as the forward velocity increases, thereby increasing the possibility of derailments at these relatively high speeds. Several ANCF examples are also presented in this investigation in order to shed light on the potential of using the ANCF liquid sloshing formulation used in the railroad field.