To analyze the thermal stratification of solar hot water storage tanks using numerical simulations, is it possible to apply the turbulence model? What are the parameters of using the model?
Depending of the goal of your study, depending on your available computational power, depending on the characteristic parameters of your flow problem you should focus first on the proper formulation (DNS/LES/RANS). Eventually, if the formulation requires a closure model you should wonder about the suitable turbulence model.
Without more details is hard to understand what you can do to simulate the problem.
In my opinion must be laminar, you can check in Bracamonte, J., Parada, J., Dimas, J., & Baritto, M. (2015). Effect of the collector tilt angle on thermal efficiency and stratification of passive water in glass evacuated tube solar water heater. APPLIED ENERGY, 155, 648-659. Elsevier Ltd. doi: 10.1016/j.apenergy.2015.06.008.
You should determine the type of problem (laminar or turbulent flow case). However you should know first the methodology to treat your problem (DNS OR LES or mixed ). In general you may read about turbulence models and its applicatoions.
If we talk solar heating, I'd think that during a day-night cycle we cannot completely exclude a heating/cooling cycle so that in the cooling phase the cooled parts "fall down" and thus generated currents which via shear production generate turbulence etc. etc. and in the stratified part of the fluid body internal waves can also not be excluded - might become complex.
In my opinion, it depends on the model that you are going to develop. Turbulence is a 3D phenomenon caused by inlet jet mixing, plume entrainment, heat losses, etc. Using CFD, of course, you can model the turbulence. However, it is not the case for one-dimensional models since temperature gradient is only considered in axial direction, but turbulence should also be considered in radial and angular directions. Followings are papers that give some hints to solve this issue:
Article A validated model for mixing and buoyancy in stratified hot ...
Article A 1-dimensional continuous and smooth model for thermally st...
I hope this reply helps!
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