MOTION OF A CYLINDER INSIDE A ROTATING DRUM
GOAL Solid - Fluid Interaction

The idea is to place a solid body (cylinder, R2) inside a horizontal rotating drum (R1) filled with water. The left figure shows a horizontal Taylor-Couette configuration and the right figure displays what we want: let the inner cylinder free to move by the internal hydrodynamic forces produced by the rotating drum flow

 schematics
 lift drag schematics


SETUP
 Rotating horizontal drum
The experimental setup allow us to measure independently the rotation frequency of the Drum, the position of the center of gravity of the inner cylinder in time (FFT tracking), the flow field (PIV velocity system) and the electrical power (mean and fluctuations) to produce the motion.
 setup measure position and speed

RESULTS
 Lift and Drag forces

The inner cylinder reaches a levitation state. Cylinder mass 7.8 gr, radii are R1 = 30 mm and R2 = 7.5 mm; Drum frequency is Ω1 = 3.4 Hz and Ω2 = 0 Hz. The equilibrium position is R⋆ and the gap ∆ between drum wall and cylinder wall is close to R2.

The figure at right shows the lift coefficient CL as a function of  the Taylor  Ta.  Data collapse is good.

 in levitation at rest
Cl vs Taylor number



uch
 Universidad de Chile, Facultad de Ciencias Físicas y Matemáticas
contact