Numerical simulation of the long-term cooling process applied to a storage tank with an internal gas flue

The transient cooling of a fluid initially at rest, inside a storage tank with an internal gas flue submitted to heat losses to the ambient is studied. In order to identify the relevant non-dimensional groups that define the transient natural convection phenomenom that occurs, a nondimensional analysis is carried out. A parametric study by means of several numerical simulations led to correlate the Nusselt number to feed simplified models based on global balances.