Question

a) Fresh water at room temperature sits in a stationary cylindrical tank as shown in the figure. A steel can filled with ice is inserted into the middle of the tank of water. Blue dye is injected adjacent to the can, and red dye is injected at the outside of the tank. Predict and sketch the pattern of circulation that will occur after the experiment has continued for several minutes, assuming that ice remains in the can and continues to cool the adjacent water (2P) f 0 Tank Can Water surface Ice Blue dye Red dye (b) The experiment is now repeated, but the tank now rotates counter-clockwise about its center (i.e. f> 0). Predict and sketch the pattern of circulation that will occur after the experiment has continued for several minutes, assuming that ice remains in the can and continues to cool the adjacent water. (3P) (Hint: think about the horizontal pressure gradients that you would expect to result from the horizontal changes in temperature in this experiment, and the flow that should result if the Coriolis force balances those pressure gradients.)

Answer 1

(a)There is a tank containing room temperature water inside which is inserted a can containing ice. The ice will start cooling the adjacent water. The temperature of the water adjacent to the can will start reducing as compared to the temperature at the far end of the tank. Cold water is denser than hot water and will start moving downwards.

Heat transfer will take place as per convection currents in water and the warm water (molecules) will start moving towards the can and at the same time the cooler water molecules will start sinking.

Time t-o ICE at. O

(b) In the second case the tank is rotating.  

side view view Red due milling to the centre Blue due mooring away the centre