- Flow control around a circular cylinder with a porous ring at
Re=30000: vorticity fields for the control-off (up) and the
porous (down) cases. A tremendous regularized flow is obtained
with the passive control as the flow changes from a chaotic
distribution of vortices to a regular Karman street behind the cylinder
(Bruneau & Mortazavi JOPE 06). Direct numerical simulations are
performed using a multigrid/penalization code.
- Passive control around a square back Ahmed body on the top of a road at Re=30000 with a porous layer
in the upper side of the obstacle (direct numerical
simulations are performed using a multigrid/penalization code):
Without control; average drag
With control; average drag
coefficient: 0.332 (-33%)
- Closed-loop active
control with two small pulsed jets implemented on the upper and lower
parts of a vertical step in a channel flow (Re=2000). The main target
control technique is to influence directly the vortex shedding and the
main recirculation zone: the upper jet changes the shedding dynamics
and the lower one perturbates and pushes away the recirculation zone.
Computations are performed using high accuracy vortex methods
(Creusé et al. 2007, submitted).
Control with oscilating inlet velocities
Control with synthetic or pulsed jets on the step
for an uncontrolled flow.
for a closed-loop controlled flow with pulsed jets on the step walls.