Analytical models for evaluating buoyancy-driven ventilation due to stack effect in a shaft considering heat transfer from shaft interior boundaries

Stack effect is a dominant driving force for building natural ventilation. Analytical models were developed for the evaluation of stack effect in a shaft, accounting for the heat transfer from shaft interior boundaries. Both the conditions with constant heat flux from boundaries to the airflow and the ones with constant boundary temperature were considered. The prediction capabilities of these analytical models were evaluated by using large eddy simulation （LES） for a hypothetical shaft. The results show that there are fairly good agreements between the predictions of the analytical models and the LES predictions in mass flow rate, vertical temperatures profile and pressure difference as well. Both the results of analytical models and LES show that the neutral plane could locate higher than one half of the shaft height when the upper opening area is identical with the lower opening area. Further, it is also shown that the analytical models perform better than KLOTE＇s model does in the mass flow rate prediction.