Hood Flutter Under Transient Aerodynamic Loads 2022-01-0762

Automobile hood design is driven by many factors, such as strict government regulations, fuel economy, weight, manufacturability, aerodynamic performance, aesthetics, structural integrity, and pedestrian safety standards. The requirement of improved fuel economy and safety regulations like pedestrian protection drive designers to reduce the thickness of the hood parts and use lighter materials. This leads to significant reduction in the hood stiffness. The hood needs to withstand steady and unsteady aerodynamic loads and meet deflection and vibration targets. The susceptibility of the hood to adverse aero load response is increased as the stiffness of the hood is reduced.

The objective of this study is to develop a methodology to simulate hood behavior under transient aerodynamic loads in controlled environments. This study mainly focuses on developing fluid structure interaction methodology to simulate the behavior of the hood system under transient aerodynamic loads.

A flat plate approach was applied to create disturbance in wind flow to simulate a vehicle in front of the target vehicle in wind tunnel. This situation is simulated using computational fluid dynamics (CFD) software to generate transient aerodynamic loads.

The CAE simulations help to understand the hood behavior under transient aero load and mitigate the risk of excessive hood vibration in early development stages of the hood design.