The Buoyancy model increments the heat exchange between layers when the upper layer is colder than the lower one.
The Buoyancy effect is defined by the following equation,
Q=G*dT*nEle^exp_nEle
G. Its value determines the buoyancy effect.
exp_nEle. The results should not be affected by the
TES's discretization. In this regard the parameter
exp_nEle is used to improve the buoyancy model,
diminishing the effect of the number of layers used on the
model.