Contribution to the Analysis of Transient Aerodynamic Effects Acting on Vehicles 2004-01-1311
The transient phenomena occurring when a vehicle exits a tunnel into a prevailing crosswind or when vehicles overtake or cross are analysed with an approach based on the assumption of pseudo-harmonic variations of the aerodynamic characteristics. The findings provide magnitudes of the frequencies and the Strouhal numbers associated with the transient variation of the side forces. Results are compared with the computational simulations of the overtaking process. The pseudo-harmonic behaviour is validated and the values of the frequencies and Strouhal numbers are verified. The transient aerodynamics is then analysed on 1/5-scale models using a test bench specially developed for simulating the overtaking process.