[MITgcm-support] Questions: simulating the cooling process of a glass of water

[Oren Raz]

Hi,
My name is Oren Raz, and I am a postdoc in Chris Jarzynski's research group
at the department of chemistry, University of Maryland College Park.

We are trying to simulate in your software the Mpemba effect, in which a
glass of hot water cools faster than identical glass filled with cold
water, when both are placed in a refrigerator. This fact was experimentally
observed long ago, and recently is under a debate, see e.g. H. C. Burridge
and P. F. Linden, Scientific Reports 6:37665 (2016). The idea is to use
your code and run "cooling experiments" from different initial temperature,
and plot the average temperature as a function of time.

After running several simulations, I have several questions which can
illuminate the results I got so far:


   1. Using the ``exactConserv.=True" option (see parameters list attached
   in the file "data"), we see that the total volume of the fluid does not
   changes during the experiment. Assuming that the temperature is always at
   least 5 celsius above the freezing point (the refrigerator's temperature is
   5 celsius), constant volume is unphysical, since the expansion coefficient
   is positive. Is it possible to track the actual volume during the cooling
   process?
   2. Our time-steps are extremely shorts: deltaT=1e-3 (seconds). In such a
   short timescale, the change is the destiny might be strongly effected by
   the change in the temperature - which if we understand correctly you
   completely neglect (1.5.1 in the user manual). Is there a way to avoid this
   approximation?
   3.  Is there a way to make sure which set of equations we are using?
   4. Is there an option to set the boundaries (other than the top
   boundary) to a constant temperature with heat exchange through the boundary?

Best regards,
Oren Raz
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