Research On Aerodynamic Characteristics And Parameter Influence Of High Speed Elevator Car Rendezvous Process

Due to the continuous emergence of high-rise buildings,in order to improve the efficiency of people in and out of buildings,high-speed elevators are more and more popular.In the design and construction of buildings,separate elevator shafts are usually reserved for each elevator.Even if the two adjacent elevator shafts need to be separated by concrete walls,in order to reduce the construction cost and improve the construction efficiency,some high-rise buildings are not for each elevator.The elevator shaft is built independently by the lift car,but a through shaft which can be operated by multiple lift cars in parallel is built.In the narrow and long closed space of the shaft,the piston effect of the high-speed elevator makes the airflow flow more intense.When two cars run in the same shaft,the airflow disturbance will be more severe.Especially when two cars meet,the air in the shaft will be compressed and released quickly,which will make the aerodynamic force of the car change sharply and affect the smooth operation of the car.Therefore,in order to explore the aerodynamic characteristics of two highspeed elevators running in the same shaft,especially when two cars meet,based on the turbulence model of fluid mechanics,this thesis established the elevator shaft car model under the influence of parameters,and carried out numerical simulation by using CFD technology,and analyzed the high-speed elevator meeting operation under the influence of the side spacing of cars,the running speed of cars,the width and height of cars.In this thesis,the aerodynamic characteristics of the system were deeply explored.Firstly,according to the characteristics of low Mach number and incompressibility of the air flow in the shaft when the elevator car was running,considering the turbulence pulsation of the air near the shaft wall and the car wall,RNG k-ε turbulence model was selected as the control equation of wellbore flow field,in order to prove the feasibility of the dynamic grid method in the numerical simulation of the aerodynamic characteristics of high-speed elevator,the well parameters of the conventional single well and single car high-speed elevator test tower of the company were made according to the project combination,ignoring the counterweight,guide rail and other components in the shaft,ICEM was used to mesh the model,and the dynamic grid method was used to simulate the operation of the car in Fluent.The wind speed at the bottom of the shaft was monitored.The measured results of the anemometer used in the experiment were compared with the numerical simulation results.It was found that the numerical simulation results were consistent with the measured results,which verified the feasibility of the simulation method,and the method was applied to the high-speed elevator in the shaft to research on aerodynamic characteristics of rendezvous.Secondly,considering the influence of the spatial layout of the car in the hoistway on the aerodynamic characteristics of the car,the comparative model of the lateral spacing of the car was established and the numerical simulation was carried out.The changes of the vertical aerodynamic resistance,horizontal aerodynamic lift,flow velocity and flow pressure of the car with different lateral spacing of the car were studied,the influence law of aerodynamic force and flow field of rendezvous operation,and the influence of the lateral spacing of the car on the two cars in the hoistway was analyzed.Thirdly,considering the influence of the speed parameters of the car,the aerodynamic changes of the two cars at different intersection speeds were explored,and the car running strategies at different speeds were modeled.The intersection of moving car and stationary car,the intersection of two cars with different running speeds,the intersection of two cars with the same running speed,and the intersection of different speeds were simulated.This paper deeply analyzed the aerodynamic force and flow field characteristics of the car operation process under different speed conditions,and explored the change of aerodynamic force fluctuation in the process of car rendezvous,which had a certain reference value for the formulation of the stable operation strategy of high-speed elevator.Finally,considering the influence of the geometric size of the car on its aerodynamic characteristics,parametric modeling of the car width and height was carried out respectively,and numerical simulation of the comparative model was carried out through Fluent.Under the condition of two high-speed elevators running in the same hoistway,the aerodynamic resistance,aerodynamic lift in all directions,aerodynamic force in all directions and aerodynamic force in the process of car motion intersection under the influence of the car width and height were explored.The width and height of the car with less aerodynamic fluctuation in the intersection operation can be obtained from the velocity and pressure changes of the transient flow field,which will help to reduce the car vibration caused by the aerodynamic changes in the process of car movement,and provide a certain reference for the geometric size design of the high-speed elevator car in the hoistway.