Development Of Experimental Setup For Aerodynamic Characteristics Of The Evacuated Tube Transport System

In this paper, the testing apparatus for ETT aerodynamic characteristics are designed and built based on mechanics and mechanism. And the testing apparatus are verified by experimental method.Four kinds of design schemes are proposed based on theoretical simulation and running characteristics:the ETT system of straight line type experiment platform, the ETT system of vacuum chamber experiment platform, the ETT system of annular pipe experiment platform, the ETT system of circular experiment platform. The ETT system of circular experiment platform is selected as the optimal design for the evacuated tube transport system by screening.The ETT system of circular experiment platform mainly includes five parts:the supporting module; the transmission module; the sealing module; the safety module and the data processing module. The 45# steel (10mm thick) is chosen as the building material for the operating platform. The power of testbed is provided by the three-phase asynchronous motor, of which the speed is controlled by a frequency converter. The power is transferred to the train model through coupler, transmission shaft and rotating arm. During the experiment, a rotary-vane vacuum pump is used for vacuumizing the operating platform, and the vacuum gauge mounted on the body of the platform, is used for measuring the pressure. The pressure is maintained by static seal and dynamic seal. The data acquisition and processing system is the core part of the evacuated tube transport system. Pressure sensors are mounted on the head and the tail of the train model, the real-time data is transferred and recorded in a PC (Personal Computer) via a Bluetooth wireless transport module.The experimental studies for the aerodynamic resistance and aerodynamic thermal characteristics are carried out. When the environment temperature and the blockage ratios are constants, the pressure fields and the temperature fields under different pressure and speed are tested. Furthermore, the change laws of aerodynamic resistance and aerodynamic thermal characteristics generated from the head and tail of the running train model. Experimental results show that:when the environmental pressure is constant, the aerodynamic resistance at the head of train model gradually increases with the train speed increases; when the Mach number is constant, the aerodynamic resistance at the head of train model gradually decreases with the environmental pressure decreases.