NURBS Curve-based Multi-objective Aerodynamic Optimization Design for Ultra-high-speed Elevator Fairings

Abstract

With the increase of elevator speed, the aerodynamic drag and lift forces of the car became more and more great, which restricted the further improvement of elevator speed, and became the key factor affecting elevator comfort and safety. In order to optimize the aerodynamic performance of the elevators, a parameterized model of the elevator systems including fairing, car, counterweight and hoistway was built using NURBS curves. Taking aerodynamic drag coefficient Cd and aerodynamic lift coefficient C1 as optimization objectives, four key design parameters with the greatest impact on optimization objectives were selected by sensitivity analysis. In order to shorten the calculation time, a Kriging model was established to carry out multi-objective optimization of the fairings by checking the independence of the grid. A series of Parcto solutions were obtained. Finally, the aerodynamic performances of the fairings before and after optimization were compared and analyzed. The results show that the aerodynamic performances of elevator systems may be improved by reducing the convexity and concavity at the side and rear of the fairings and increasing the total height and rear height of the fairings. After optimization, Cd and C1 of the fairings are reduced by 26.67% and 34.27% respectively, and they have good applicability under different ladder speeds.