Universal modeling of unsteady airflow in different hoistway structures and analysis of the effect of ventilation hole parameters

Abstract

Accounting for the strong flow field in a hoistway during the operation of an ultra-high-speed elevator and reasonable ventilation in engineering practice, installation of ventilation holes (VH) is important. First, based on Bernoulli’s principle for unsteady flow, the unsteady airflow in hoistways without VH, with one pair of VH, and with two pairs of VH were modeled theoretically. Based on these three models, a universal theoretical model of unsteady airflow in a hoistway with multiple VH was deduced. The validity of the theoretical model was verified by comparing the theoretical velocity coefficients with those obtained experimentally in an elevator test tower. Finally, the influence of different VH parameters on the airflow were analyzed. The results showed that the weakening trend of the airflow movement in the hoistway decreased gradually when the cross-sectional areas of the VH increased. The change in the VH length had little effect on the airflow movement in the hoistway, and the change in the opening position of the VH had a significant effect on the airflow in the hoistway. With the increase in the number of VH with the same cross-sectional areas, the weakening trend of the airflow in the hoistway was gradually reduced.