Thermal Mass of the water in CDF HELP ME PLZ!!!

[savchenko0825]

I`m a grad student and working on my thesis, part of which is to conduct energy modeling and analysis of the giant swimming pool attached to the house. I want to run the CFD simulation of the pool for the hottest and coolest days of the year to see what water temperature I can get from passive strategies (solar and geothermal gain). The pool is covered with the fabric structure (therefore almost no insulation).There is several restrictions I ran into in my model:

1) Basically swimming pool is a room with a cover of uncoated glass with transmittance of 1 (both reflectance and absorb. are 0) where the glass is meant to simulate the water surface. The model doesn`t count on thermal mass of the water because it sees the pool as a room (and so it has air inside) and therefore don`t reflect appropriate results. I tried both approaches:
- created thick walls with material that has physical characteristics of water and sort of eating most of the space inside the room;
- changed the furniture mass factor (5 instead of default 1) in the systems templates;

I ran CFD analysis separately for both mentioned approaches importing boundary conditions for the day and time with max mean radiant temp, but I`m concerned that the model does not look realistic.

Have you ever done or do you have any recommendations of how to go around the air in the room and make the model see it as a pool with water and count on its thermal mass?

2) My pool is a space dug in the ground with a minimal 1mm insulation of R-value of 0.2. Therefore I would like to analyze how does the pool interact with ground in terms of heat gains/sinks. I do not necessarily need to get the particular numbers or run CFD for ground layer attached to pool (would be good, but not smth really required). I`m more concerned about the boundary conditions between ground and the water in the pool, and how to mirror the change of ground temperatures through the year so the model recognize it and count on it in combination with solar gain while performing pool`s CFD analysis.

I tried to put my pool into the adjusted building and sort of assigned the const temperature to it, but I`m not sure if it really does what I need.

Is there anything you can recommend me on this issue?

So summing up, I`m struggling with showing the water thermal mass in the pool (so getting that heat accumulating effect) and making sure that the conduction through the ground is taken into consideration.
Have you ever deal with such a task and do you have any suggestions?

I would really appreciate any feedback from you!

Thank you very much,

Best regards,
Anastasiia

[harshadj]

On top of my mind, I think you would need to adjust your weather file according the wind and other factors.

e.g. I think if the wind was coming in from swimming pool side, it would high a slightly higher moisture content than other directons. the temperature of air could be slightly lower in summer and slightly higher in winter etc. You would basically need to analyse the microclimate around the house as affected by the swimming pool and and make suitable adjustments.

VE is a package to analyse occupied spaces. Occupied spaces are generally filled with air rather than water (other than Atlantis )