Rotating tank experimentation-Sloping Bottom

Constructing the rotating tank:

        For this Spring semester I have designed a new model to help create a visualization for authentic Rossby Waves utilizing a sloping bottom design to mimic this effect.With the help of my FURI (Fulton Undergraduate Research Initiative) mentor-Dr. Huei-Ping Huang and the research machinist at ASU's machine shop this was possible to make this newly created design of a sloping bottom.For the laboratory experiment, we have built a sloping bottom for the rotating  tank. The sloping bottom, when inserted to the existing tank, will allow a variation of the depth of fluid with “latitude”. This will then allow a more realistic generation of “Rossby waves’ in the tank. Such waves are commonly observed in Earth’s atmosphere. They are relevant to the regulation of climate variability at higher latitudes.  We have finished the design of the sloping bottom and submitted it to ASU’s research machine shop.  It will be made of a metal sheet, similar to the existing inner cylinder of the rotating tank. A new set of experiments will be conducted with the rotating tank plus a sloping bottom.  If schedule allows, the outcome of those experiments will be compared to the experiments without a sloping bottom as well as the numerical simulations using Fluent.

Mass properties of Slope_1060_Aluminum

Output  coordinate System:

Density = 0.10 pounds per cubic inch

Mass = 21.12 pounds

Volume = 216.48 cubic inches

Surface area = 379.90 inches^2

Center of mass: ( inches )

    X = 0.00

    Y = -2.47

    Z = 0.00

Principal axes of inertia and principal moments of inertia: ( pounds * square inches )

Taken at the center of mass.

     Ix = (0.00, 0.00, 1.00)       Px = 212.63

     Iy = (1.00, 0.00, 0.00)       Py = 212.63

     Iz = (0.00, 1.00, 0.00)       Pz = 399.98

Moments of inertia: ( pounds * square inches )

Taken at the center of mass and aligned with the output coordinate system.

    Lxx = 212.63    Lxy = 0.00    Lxz = 0.00

    Lyx = 0.00    Lyy = 399.98    Lyz = 0.00

    Lzx = 0.00    Lzy = 0.00    Lzz = 212.63

Moments of inertia: ( pounds * square inches )

Taken at the output coordinate system.

    Ixx = 341.39    Ixy = 0.00    Ixz = 0.00

    Iyx = 0.00    Iyy = 399.98    Iyz = 0.00

    Izx = 0.00    Izy = 0.00    Izz = 341.39

Figure2. Solid works model of sloping bottom.

Mass properties of Slope_1060_Aluminum

Output  coordinate System:

Density = 0.10 pounds per cubic inch

Mass = 13.36 pounds

Volume = 136.99 cubic inches

Surface area = 522.54 inches^2

Center of mass: ( inches )

    X = 0.00

    Y = -2.56

    Z = 0.00

Principal axes of inertia and principal moments of inertia: ( pounds * square inches )

Taken at the center of mass.

     Ix = (0.00, 0.00, 1.00)       Px = 164.74

     Iy = (1.00, 0.00, 0.00)       Py = 164.74

     Iz = (0.00, 1.00, 0.00)       Pz = 309.37

Moments of inertia: ( pounds * square inches )

Taken at the center of mass and aligned with the output coordinate system.

    Lxx = 164.74    Lxy = 0.00    Lxz = 0.00

    Lyx = 0.00    Lyy = 309.37    Lyz = 0.00

    Lzx = 0.00    Lzy = 0.00    Lzz = 164.74

Moments of inertia: ( pounds * square inches )

Taken at the output coordinate system.

    Ixx = 252.13    Ixy = 0.00    Ixz = 0.00

    Iyx = 0.00    Iyy = 309.37    Iyz = 0.00

    Izx = 0.00    Izy = 0.00    Izz = 252.13

  The main point of the slope is to create authentic Rossby Waves. In our figures, in the upper layer of the tank the temperature gradient is unaffected. Now, if the system is too stable the flow will not break and this is depicted in our figures. In most of these pictures one can see tank's temperature gradient in the upper level (due to the slope) being affected;however, in the middle of the tank it's not and this could be a possible cause of why the flow is so stable and not "breaking". Another issue we will have to fix is at the bottom of our tank the water is much colder therefore much denser so when the flow starts the problem of leakage arises and automatically sinks down.We are not particularly concerned if the water is very dense at the bottom of the tank but more concerned with the layer of water at the top to have a differential temperature contrast. Therefore, we will add a substance inside the inner cylinder so that we can focus on the top half of our inner cylinder to be filled with ice instead of the entire inner cylinder. In our second experiment we usually have to wait for the tank to spin up, but we didn't in this case and this is what caused the dynamical flow to behave in this manner.