G051022 自動車の車体形状と空力特性([G051-02]流体工学部門,一般セッション : 空力特性他)

抄録

Aerodynamic characteristics have great influences on vehicle performance. In order to improve the aerodynamic characteristics, it is necessary to clarify structure of the flow about the body. The aim of this research is to analyze the influence of configurations of road vehicles on aerodynamic characteristics. As configuration parameters, the rear window angle and the side window angle are adopted, and totally 33 patterns of configurations changing from box type through fastback to notchback types are investigated by wind-tunnel experiments. As results, in the cases of side angles 0° and 15° , the drag was increased at rear angles between 25° and 30°, while in the case of side angle 30° this tendency was not detected. In the whole cases it was shown that the more the side windows is slanted, the less the drag is. The factor is that when the inclination of the side window becomes large the angle between the rear and side surfaces becomes obtuse, and the formation of longitudinal vortices is restrained. The flow visualization by tufts and the five-hole pitot tube detected the trailing vortices, and the factor was confirmed.