variavel0=<b>Roberto da Mota Girardi</b> - girardi@aer.ita.br Instituto Tecnológico de Aeronáutica (ITA)
<b>Luis Carlos Pires Videira</b> - videira@embraer.com.br EMBRAER
<b>Abstract.</b> The present work is part of a wide research concerned to the flow on ground vehicles, more specifically buses. The results obtained indicate that the wake flow can be influenced by interference elements. In the 2D bluff bodies, the use of splitter plates has shown efficient in the increase in the base pressure coefficient, resulting a drag coefficient decrement. Ground vehicles are bluff bodies with a wide wake that interacts with the floor. The present work goal is to verify interference elements influence on the wake topology and on the pressure coefficient at a bus model rear surface. The experimental techniques used in the study were: flow mapping by using a hot wire anemometer fixed at a three axis traversing system for measurements of the average and fluctuations velocities and a manometer used to obtain the pressures in the rear surface. A data acquisitions system was used to perform the experiments and the flow mapping (velocity fields) and pressures results are analyzed together, in order to find correlations between wake topology and the base pressure distribution. Great changes in the wake topology were obtained when the interference element length was increased, resulting in 30% increment of the average base pressure, which is associated to the bus base drag.
<b>Keywords.</b> Vehicles Aerodynamics, Bluff Body, Experimental Methods, Bus Wake.