SUPPRESSION OF PERIODIC VORTEX SHEDDING FROM A ROTATING CIRCULAR CYLINDER

1
SUPPRESSION OF PERIODIC VORTEX SHEDDING FROM A
ROTATING CIRCULAR CYLINDER
Background
Rotating Cylinder
Rotation of a cylinder can substantially alter
the behaviour of the wake with respect to the
stationary case. The strength of the shed
vortices was measured as part of an evaluation of
the stability criterion for the formation of a
vortex street.
Spinning Missile
Objective
To examine the effect of rotation on the strength
of the vortices as the velocity ratio, ?, is
altered.
2
Research Carried Out
Stability Criterion
Hot- Wire PIV Smoke- Wire
Key Findings


Vortex street is stable for circulation ratios ?
?1 / ?2 in the range 0.382 lt ? lt 2.618, where
?1 and ?2 are the strength of vortices in the
upper and lower rows of a vortex street. For ? gt
2.0 periodicity is suppressed.
Non-rotating Case (? 0)
Rotating Case (? 2.7)