Fluid Structure Interaction Simulation of Hood Flutter

Fluid structure interaction problems appear in a wide range of industries, including automotive, marine and aerospace. In the automotive industry, the drive to make components lighter can also reduce their stiffness, causing them to deflect significantly under aerodynamic loads. The deflections can affect the aerodynamic properties of the vehicle, cause dynamic fluctuations that are visible to the driver, or even lead to failure. The Incompressible Computational Fluid Dynamics (ICFD) solver in LS-DYNA® is well suited to simulating fluid structure interaction as the code provides a range of robust and easy to use coupling algorithms and both solid and fluid solver can be readily accessed from within the same simulation environment. This paper shows some of the capabilities in LS-DYNA for simulating hood flutter, which is a known fluid-structure interaction problem. Hood flutter is affected by the turbulent wake from preceding vehicles, the hood opening mechanism and the opening up of seals. This paper considers the feasibility of commercially feasible simulation of this complex automotive FSI phenomenon through the creation of a series of models which display how the important physical features of hood flutter could be modelled.