Simulation Analysis Of Aerodynamic Characteristics Of Hyperloop Vacuum Pipeline Vehicle

The vacuum pipeline transportation system has the advantages of speed,convenience,safety,environmental protection,and high e fficiency.It is a strong complement to the existing road transportation,railway transportation,water transportation and air transportation,and has broad application prospects and market value.Due to the special operating environment of transonic speed and low pressure,the aerodynamic performance of the vacuum pipeline vehicle is quite different from that of aircraft,trains,and cars in an open environment.The study of the thin aerodynamic characteristics of high-speed vacuum pipeline vehicles can provide important theoretical basis and technical support for the design and construction of high-speed vacuum pipeline transportation systems in China.In this thesis,based on the computational fluid dynamics method and numerical simulation technology,the two-dimensional model and three-dimensional model of the vacuum pipeline vehicle system are established.Using the established model,the aerodynamic characteristics of pipeline vehicle are calculated and analyzed.The specific research content of this thesis is as follows:1)The flow field during the operation of the vacuum pipeline vehicle under different environmental parameters was simulated and calculated.It was found through comparison and analysis that the aerodynamic drag and lift of the pipeli ne train during operation increased with the increase of the operating pressure;At low speeds,the aerodynamic drag and aerodynamic lift of pipeline vehicle are close to proportional to the square of the train speed,but the growth rate will be slowed to a certain extent after reaching a certain speed;The air drag coefficient of the pipeline vehicle increases with the increase of the blockage ratio,but the air lift coefficient has a large and irregular change range after the blockage ratio changes.2)The CFD simulation of the pipeline vehicle models with different shape was carried out,and the aerodynamic drag coefficient and lift coefficient of the pipeline vehicle under different modeling conditions were obtained;A comparative analysis of the results reveals that the aerodynamic drag coefficient and the aerodynamic lift coefficient of the pipeline train are inversely proportional when the other conditions remain unchanged and only the shape is changed;The three-dimensional model before and after optimization of drag reduction modeling is selected for verification,and it is found that the aerodynamic drag coefficient of the optimized model decreases while the aerodynamic lift coefficient increases to a certain extent.3)The effect of aerodynamic lift on th e Passenger comfort of the pipeline vehicle is explained;Taking a typical route from Los Angeles to San Francisco designed in the Hyperloop system plan as an example,the running time and running speed of pipeline trains in the four parts of this route ar e introduced in detail;The characteristic speeds of these four parts were selected for CFD simulation analysis,and the relationship between pipeline train running time and aerodynamic lift values in each part of the route was obtained.The work of this thesis is to study the aerodynamic characteristics of pipeline vehicles under different environmental parameters and various conditions,mainly the changes of aerodynamic drag and lift,and try to find the rules of the aerodynamic characteristics of pipeline vehicles under the changes of related conditions.Hope that it can be used as a reference for the future application of pipeline vehicle.