Geoscience Reference
In-Depth Information
2 Methods
Experiments were performed in a cylindrical tank with radius
R
tank
¼
0.3 m,
mounted on a rotating table (Fig.
1
). The whole depth of the tank was 0.24 m. In
half of experimental runs, the bottom was horizontal but in other half of them
the tank was equipped by a sloping bottom (slope angle
39
, fluid depth
was increasing toward the center of the tank). The tank was filled with fresh
distilled water. Experiments were performed: (1) with rotation, for rotation periods
of 5, 10, 15 s and Coriolis parameter
f
a ¼
2.5, 1.25, 0.8 s
1
, respectively; and (2)
without rotation. To reproduce the warm buoyant jet, the circular heating cable belt
of 0.01 m thickness was used. It was mounted on the top of the water layer along the
round wall of the tank. Series of experiments were performed using various specific
power supplies
q
(25.7, 13.1, 6.37 Wt/m). The water temperature was controlled
near the wall, at the middle of the radial distance, and at the center of the tank by
three calibrated thermometers. For visualization of the buoyant jet and surface
currents, the electrochemical thymol blue indicator technique and small paper
pellets were used.
At the beginning of each experimental run, the tank was filled with fresh water
that contained thymol blue indicator with concentration of about 25 g/65 L of water.
To avoid vertical convection, the water temperature in the tank was 1-2
C below
the air temperature. Before the beginning of the experiments with rotation, the
rotating frame was switched on and the fluid in the tank was brought to solid-body
rotation state. After that, the video record was switched on; the heating cable was
initiated as a heater. Due to the electrochemical reaction, thymol blue solution near
¼
Fig. 1 Experimental setup.
1
- rotating table,
2
- slope,
3
- tank wall,
4
- video
camera,
5
-
autotransformator,
6
- ampermeter,
7
- voltage
supply,
8
- copper plate
(anode),
9
- heating
resistance isolated cable,
10
,
12
- outlets,
11
- nichrome
wire (cathode)
