Research On The Train Induced Airflow For The Security Monitoring Application

At this stage, because the lack of power supply, freight vehicle cannot carry safety monitoring and early warning system, and yet, air movement always accompanied by a moving train, the basic research of this airflow on the freight vehicle in the thesis as follows:First, based on the management status of the use of freight train, and the operation stability evaluation method, we plan that the airflow can supply power for the monitoring system, the speed and acceleration measurement of vehicles can determine the operational safety and give early warning signals, GPRS system can communication with the ground monitoring system.Second, studied the airflow distributed over the moving vehicle, known that the airflow normal distance outside of lm to the roof or 0.2m to the bottom, the relative velocity between these airflow and vehicle is close to the train speed, the airflow energy relative proportional about the wind wheel area and airflow speed's cubic, in little yaw(±10%), the airflow energy changed little.Again, because the relative velocity between these airflow and vehicle is close to the train speed, measuring airflow speed to indirect measure vehicle speed, making the wind speed instruments design related to a complex work environment, the results show that the best install place at the bottom of the train, the maximum amendments of all installation location's measured value is about 1.5m/s..Finally, contrast the vertical axis and horizontal axis wind turbine, when under the high-speed airflow environment the vertical axis wind turbine energy utilization coefficient is not high enough, and cannot direct-drive motor. So we determined to use the three blades horizontal axis wind turbine, and through the relevant calculations and experiments to verify the freight vehicles airflow-based monitoring system is feasible, calculated at the train speed of 22km/h, the radius of the 100mm of the wind turbine is expected to get the energy to reach 0.875W.In summary, the paper argues that the freight vehicle airflow-based monitoring and alarm system can be applied to rail, and it is worthy of further study.