Computational Study of Unsteady Road Vehicle Aerodynamics Including Fluid-Structure Interaction

Abstract

In the study of road vehicle aerodynamics it is often assumed that the vehicle is a rigid body, rigidly attached to the ground. However, that is not the case of real vehicles on the road. They interact with the incident wind, which changes intensity and direction in an unpredictable way and also with bumps and surface imperfections of the road. The interaction between wind and vehicle can be numerically modeled as a fluid-structure interaction (FSI) problem while the road imperfections as an stochastic input force in the system.
However, even at present days, with large computational resources available, experiments are preferred to numerical simulation in the study of vehicle aerodynamics and even in the analysis of FSI problems due to the reliability gained by wind tunnels. Nevertheless, this experimental tool has also shortcomings that can be corrected and even strengths that can be improved by using numerical simulation.
In this work the feasibility of using a computational code to reproduce the experimental conditions in a wind tunnel test section is investigated. This study is focused not only on the aerodynamics of a simplified road vehicle but also on its dynamic interaction with an incident wind flow. The fluid-structure interaction model was tested and the results demonstrated that the computational tools developed in this work enable us to reproduce and/or to assist experimental studies.