Lateral Vortex Dynamics behind Ahmed Body

0352476 - ÚT 2011 RIV DE eng A - Abstract
Uruba, Václav
Lateral Vortex Dynamics behind Ahmed Body.
81st annual meeting of the international association of applied mathematics and mechanics. Karlsruhe, 2010. s. 1-1. ISBN N.
[GAMM annual meeting 2010 /81./. 22.03.2010-26.03.2010, Karlsruhe]
R&D Projects: GA ČR GA101/08/1112; GA ČR GAP101/10/1230
Institutional research plan: CEZ:AV0Z20760514
Keywords : lateral vortex * dynamics * bluff body
Subject RIV: BK - Fluid Dynamics

Structure of the wake behind the Ahmed body is strongly affected by slant angle of the rear window. Besides the classical wake consisting from back-flow turbulent region, the vortex wake system takes the form of two counter-rotary lateral vortices starting at a separation line on the roof with an open separation bulb located at the upper part of the rear window. The dynamical behavior of the longitudinal vortex pair is studied in details experimentally using the Stereo Time-Resolved PIV method. The Bi-Orthogonal Decomposition method (BOD) is utilized to calculate energetic modes, while Principal Interaction Patterns method (PIPs) is used for evaluation modes according to their stability features. Two variants of Ahmed Body with slat angle 25 and 35 degree are investigated respectively. Comparison shows considerable differences in the vortex pair dynamics of the cases in question.
Permanent Link: http://hdl.handle.net/11104/0191977