Aerodynamic performance of double car systems running the whole process in high-speed elevators under the influence of key parameters

Significant piston effects occur when the high-speed elevator double car systems operate in opposition. Particularly, when the two intersect, the aerodynamic forces operating on the car undergo an immediate alteration, significantly affecting the stability of elevator operation. This research aims to examine the aerodynamic performance and flow field distribution of double car systems operating under multiple parameters. It first develops a three-dimensional, multi-parameter, universal geometric model of double car systems and introduces a six-region dynamic layering numerical simulation method based on this model. The accuracy of the numerical model and methodology is validated through actual elevator experiments. The impact of double car spacing, blockage ratio, and the length ratio of the car to the hoistway on the aerodynamic performance and airflow distribution surrounding double car systems during the whole operation is examined. Furthermore, the aerodynamic performance of the intersection of the double car systems is examined in detail. The research findings indicate that a reduction in distance from 110 to 50 cm leads to a 46.5% rise in the peak lift value. As the blockage ratio rises from 47.5% to 62.5%, the peak drag value diminishes by 36.8%. Nevertheless, as the length ratio escalates from 68.8% to 92.8%, the peak lift value practically doubles. The research has important reference values for exploring aerodynamic performance and the value of structural parameters when double car systems run the whole process in a high-speed elevator.