SPINUP/SPINDOWN

ILLUSTRATE TIMESCALES FOR MOTION IN ROTATING AND NON-ROTATING FLUIDS, AND THE EFFECT OF SYMMETRY ON STATES OF MOTION.

The setup uses the Rotating Table Facility along with:

1. A circular dish equipped with thymol blue trigger wires.
2. Or, square or circular dishes that use particle suspensions for visualization.  

The two images below show the tanks:

The thymol dye cylinder needs a white background.  The square (shown) or cylindrical tanks with silicone oil and aluminum flakes need a black background.  The tanks should be centered on the rotating table as shown below.  Fill the dye tank to a depth above the top wire with Thymol Blue.  Fill the square tanks with 2centistoke silicone oil laced with aluminum flakes.  Suspend the flakes with a paint brush.  After completion save all fluids.  Use a big funnel, especially for the silicone oil that likes to run everywhere.

Typical setup of the thymol cylinder on the axis of the rotating table.  Connect the dye wires to the DC input from the grey-box power supply.  Pulsing the wires produces dye that can be tracked.

The general procedure is:

1.  Set the system into solid rotation (or do spin up from rest).  
2. Impulsively change rotation speed (up or down, or up from rest).  If using the dye wires, pulse them before changing the rotation speed.
3. Observe propagation of spinup fronts, general spinup timescale, structures during spin-up  The structures in the square container have interesting symmetries (see movies).

QT MOVIES OF SPIN UP USING ALUMINUM FLAKES IN CYLINDRICAL AND RECTANGULAR CONTAINERS:

1. SPIN DOWN IN A CYLINDER   (BIG SCREEN VERSION)
2. SPIN UP FROM REST IN  A CYLINDER  (BIG SCREEN VERSION)
3. SPIN DOWN IN A RECTANGLE  (BIG SCREEN VERSION)
4. SPIN UP FROM REST IN A RECTANGLE  (BIG SCREEN VERSION)
5. SPIN UP FROM  REST IN A RECTANGLE - FAST END ROTATION

SPIN UP IN A CYLINDRICAL CONTAINER WITH THYMOL BLUE VISUALIZATION