I try to model a stratified storage tank making use of water as the storage medium. The storage makes use of two ports of inlet and outlet for charging & discharging of heat.
I use the multi-node method (details given in the article). So the whole storage volume is split into several segments through its vertical direction. For each node, I need to calculate the heat loss from the node to the environment (as well as other heat and mass transfer to/from each segment). The focus here is only on the heat loss from a stratified storage tank!
I have difficulty in finding the method to obtain the convective heat transfer coefficient taking part for the storage water inside the tank. Are there any Nusselt correlations for such large cylinders (e.g. Dittus-Boelter, Gnielinski Correlation etc.) to calculate the internal convective heat transfer coefficient?
As you can guess, in this multi-node approach I will assume a constant temperature at each node/segment so no concerns of the heat loss from the stratified zone (since multiple segments/nodes together enclose to the stratified zone but each has a unique constant temperature). So the question is that: how to calculate the convective heat transfer coefficient of a water body segment residing in a large circular duct and/or at low Reynolds conditions? Another case is a no-flow condition for the storage tank (when no dis/charging occurs). This has to be considered as well in my storage tank model. Can you also help in this?
Regards.
Edited by HumanistEngineer, 06 June 2018 - 09:43 AM.