Aerodynamic Stability Analysis of Vehicles under Vehicle Meeting Conditions Based on Aerodynamics and Multi-body Dynamics Coupling

The rapid growth of the automotive industry has accelerated the adoption of lightweighting technologies, yet increased body lightweighting heightens the risk of high-speed instability. To address this, the present study develops an aerodynamics and multi-body dynamics coupling (AMC) framework that couples Star-CCM+ for CFD simulations with Adams/Car for multibody dynamics analysis to investigate aerodynamic stability during vehicle meeting conditions. A full-scale ۱:۱ CAERI vehicle model is employed, with relative vehicle motion captured using an overset mesh technique. Validation against wind tunnel tests confirms drag and lift coefficient errors below ۵%. The study analyzes transient flow fields, as well as time- and frequency-domain features of aerodynamic loads, moments, and dynamic responses under meeting speeds of ۱۵–۳۰ m/s with a ۰.۸ m lateral spacing. Findings reveal pulse-like fluctuations in side force, roll moment, and yaw moment, which drive lateral vibrations. Their amplitudes and frequencies increase with higher meeting speeds due to intensified turbulence and pressure gradients. Spearman correlation analysis shows strong positive correlations between lateral acceleration and both side force and lift, while roll angle exhibits a pronounced negative correlation with roll moment. Yaw rate demonstrates significant correlations, being negatively associated with side force and positively with roll moment.

کلیدواژه ها:

Vehicle aerodynamics ، Multibody dynamics ، Overset mesh ، Vehicle meeting ، Stability analysis