Aerodynamic Analysis And Optimization Design Of Ultra-high Speed Elevator Key Components

Modern elevator technology is developing in the direction of high speed, intelligence, and comfort. With the improvement of the elevator speed, the ultra-high speed elevator running within narrow, long shaft will cause a series of aerodynamic problems including aerodynamic drag, aerodynamic noise and low frequency vibration, which will bring great challenge to the elevator ride comfort and safety. In this dissertation, the effects on the ultra-high speed elevator aerodynamic characteristics of key component of elevator including counter-weight, shaft vents and car airflow shroud is analyzed, the aerodynamic optimization method based on the approximate response surface model is proposed to optimize the aerodynamic characteristics of the ultra-high speed elevator.The main contents of the dissertation are as follows:In the first chapter, the development of elevator technology and the current research situation of high speed elevator aerodynamic noise, aerodynamic force and aerodynamic optimization method are reviewed, the aerodynamic optimization method is proposed for high speed elevators aerodynamic design. In the end, the background, major content and framework of the research is presented.In the second chapter, the dissertation introduced the aerodynamic characteristics numerical simulation method of ultra-high speed elevator and basic fluid theory including mathematical model of fluid flow, turbulent flow numerical simulation method and its solving method, simulates the movement process of car and counter-weight in opposite direction, analyses the basic characteristics of aerodynamic force and the influence on the aerodynamic force of car speed and the distance between car and counter-weight in the process.In the third chapter, the air flow and pressure of air particles in the elevator shaft are analyzed in theory, and the relationship between velocity and time of air and car under ideal conditions is obtained, the air velocity changing curve is calculated by fourth order Runge-Kutta method. The design principle of shaft vents is introduced, the3D model of ultra-high speed elevator with shaft vents is constructed and simulated, and the influence of shaft vents on the air velocity and air distribution is analyzed in the end.In the fourth chapter, the dissertation studies aerodynamic resistance characteristics of ultra-high speed elevator in the process of movement in the shaft, designs a good streamline airflow shroud-semi-ellipsoid airflow shroud by analyzing the source of aerodynamic drag of ultra-high speed elevator and the flow field on the surface of elevator car. Then, parametric modeling and numerical simulation of ultra-high speed elevator with semi-ellipsoid airflow shroud was carried out, and the influence of airflow shroud structure on pressure distribution on the surface of car and the aerodynamic resistance is analyzed.In the fifth chapter, the dissertation introduces the gradual global approximate modeling method into aerodynamic optimization of ultra-high speed elevator on the analysis aerodynamic characteristics of key parts of high-speed elevator, puts forward aerodynamic optimization design of ultra-high speed elevator based on the approximate response surface model, and solves the model with the artificial fish algorithm. The method above is applied to aerodynamic optimization of KLWG21m/s ultra-high speed elevator, the optimal aerodynamic parameters are obtained, and the optimization results are compared with the simulation analysis results which verifies the error precision and the accuracy of the optimization results.In the sixth chapter, the further research is put forward after summarizing all the content and achievements of the dissertation.