Rollover Stability Analysis of a Double-Deck Bus Under Crosswind Effects by Computational Simulation

CASTRO, HUGO G.; PAZ, RODRIGO R.; DEL PIN, FACUNDO; CALDICHOURY, I.

New York

Congreso; 13th World Congress on Computational Mechanics; 2018

Every road vehicle under motion experiences forces and moments caused by different sources, being the wind one of the most important. Historically, several researches (computational and experimental) have dealt with the effects of the wind over road vehicles [1]. Particullarly, high sided road vehicles (e.g., double-deck buses) are highly demanded because their passenger transportation capability, being the most used mean of passenger transportation in some countries of Latin America. This type of vehicle have its centre of mass in a relatively high location so in combination with moderate velocities may give rise to rollover instabilities [2]. This scenario is further dangerous when the vehicle motion is developed along a road bend, adding lateral forces due to the centrifugal acceleration effect. In this work, as a typical application of a coupled analysis, an unsteady aerodynamics simulation of a simplified double-deck bus in windy conditions is demonstrated, and the effects of the unsteady aerodynamics on the bus motion are investigated. The obtained results are compared with the results of a conventional quasi-steady analysis. The effects of the aerodynamics clearly indicate the importance of estimating the unsteady aerodynamic forces in a vehicle motion analysis.[1] Fuller, J.; Best, M.; Garret, N.; Passmore, M.; ?The importance of unsteady aerodynamics to road vehicle dynamics?, Journal of Wind Engineering and Industrial Aerodynamics, 117 pp. 1-10, 2013.[2] Dorigatti, F.; Sterling, M.; Rocchi, D.; Belloli, M.; Quinn, A.D.; Baker, C.J.; Ozkan, E.; ?Wind tunnel measurements of crosswind loads on high sided vehicles over long span bridges?, Journal of Wind Engineering and Industrial Aerodynamics, 107-108 pp. 214 ? 224, 2012.