Akademik Veri Yönetim Sistemi
International Journal of Automotive Engineering and Technologies, cilt.7, sa.2, ss.99-109, 2018 (Hakemli Dergi)
Flow structure and other aerodynamic properties such as drag and lift
coefficients of one of the extensively investigated generic cars so-called
Ahmed body are reported in the present numerical study for the fixed ground
and upswept rear. For this purpose, Ahmed body with the slant angle of 25 is
considered and its rear bottom edge is upswept with various angles from 5 to
30 by 5 increments without any side plates. It is observed that the sizes of
the upper and lower recirculation bubbles seen in the profile section are
decreased compared with the classical Ahmed body, however, the existence
of some additional recirculation bubbles are observed when the upswept
angle increases. At the highest upswept angle, the upper and bottom vortices
called counter-rotating vortices (CVP) become nearly symmetric in the nearfar region however they merge and only one CVP forms behind the body in
the far-field. Effects of the upswept angles on the drag and lift coefficients
reveal that drag coefficient reduces the upswept angle to 15and then rises at
20 while lift coefficient increases after 25