LES INVESTIGATION OF THE ASYMMETRY IN THE WAKE OF A GENERIC VEHICLE BODY

Paper i proceeding, 2013

Large eddy simulations are used to investigate the emergence of flow asymmetry behind the symmetric geometry of a simplified notchback vehicle body. Two different angles of the backlight were simulated, resulting in asymmetric and symmetric flows in agreement with previous experimental observations. Simulations were made at Reynolds numbers 10^4, 3 x 10^4 and 5 x 10^4 based on the incoming velocity and the height of the body. The Reynolds number dependency of the asymmetry phenomenon was observed when the Reynolds number was changed from 10^4 to 3 x 10^4. The LES results are used to present a new picture of the time-averaged flow around the notchback geometry. The instantaneous flow was found to contain regular shedding of the horse-shoe vortices from the deck at the nondimensional frequency of St=0.42, in agreement with previous experimental observations.