Analogies between oscillation and rotation of bodies induced or influenced by vortex shedding
Abstract
Vortexinduced or vortexinfluenced rotation and oscillation of bodies in a parallel flow are discussed. A steady flow occurs if the body axis is parallel to the flow or if the axis of rotation is perpendicular to the flow. Flows around an oscillating body are quasisteady only if the Strougal number is much smaller than unity. The connection between rotation and oscillation is demonstrated in terms of the autorotation of a Lanchester propeller, and conditions for stable autorotation are defined. The Riabouchinsky curve is shown to be typical of forces and torques on bodies with vortical wakes, including situations with fixed body axes perpendicular to the flow. A differential equation is formulated for rotational and oscillating bodies that shed vortices by extending the pendulum equation to include vortical effects expressed as a fifthorder polynomial.
 Publication:

Vortex Motion; Proceedings of the Colloquium
 Pub Date:
 1982
 Bibcode:
 1982vomo.proc...82L
 Keywords:

 FluidSolid Interactions;
 Oscillations;
 Rotating Bodies;
 Vortex Shedding;
 Airfoils;
 Flat Plates;
 NavierStokes Equation;
 Parallel Flow;
 Periodic Variations;
 Fluid Mechanics and Heat Transfer