scholarly journals Characteristic analysis of air pressure wave generated by high-speed trains traveling through a tunnel

2012 ◽  
Vol 20 (1) ◽  
pp. 31-35
Author(s):  
Chuanhui Wu ◽  
Xiangling Gao ◽  
Pinxian Gao
Keyword(s):  
Pressure Wave ◽  
High Speed ◽  
Air Pressure ◽  
Characteristic Analysis ◽  
High Speed Trains

Iterative learning control of air pressure variation inside a high-speed train under the excitation of the tunnel pressure wave with a fixed-morphologic form

2021 ◽  
pp. 095440972110327
Author(s):  
Zhiying He ◽  
Chunjun Chen ◽  
Dongwei Wang ◽  
Chao Deng ◽  
Jia Hu ◽  
...  
Keyword(s):  
Iterative Learning Control ◽  
Pressure Wave ◽  
High Speed ◽  
Learning Control ◽  
Pressure Variation ◽  
Iterative Learning ◽  
Air Pressure ◽  
High Speed Train ◽  
Comfort Index ◽  
Simulation Signal

Based on the characteristics that the tunnel pressure wave has a fixed-morphologic form when the same train passes through the same tunnel, an applicational approach based on the iterative learning control (ILC) is developed, aiming at overcoming the drawbacks of the traditional strategy for controlling the air pressure variation inside a high-speed train carriage. To achieve the goal, the control system is mathematically modelled. Then, the problem is formulated. The task of suppressing the influence of the tunnel pressure wave on the air pressure inside the carriages is shifted as an ILC problem of tracking the comfort index with varying trial length. The algorithm of refreshing the control signal from trial to trial is determined and the process of ILC control is designed. Next, the convergence of the newly-developed applicational ILC algorithm is discussed and the algorithm is simulated by the simulation signal and field-test signal. Results show that the applicational ILC algorithm be more adaptable in handling the control of the air pressure inside carriage under the excitation of varying-amplitude, varying-scale and varying-initial-states tunnel pressure wave. Meanwhile, the matching with tunnel pressure wave makes the applicational ILC algorithm will take both the riding comfort and fresh air into consideration, which upgrades the performances when the high-speed train passing through long tunnels.

Analysis of Dynamic Wind of Sound Barrier under High Speed Train

2013 ◽  
Vol 361-363 ◽  
pp. 1536-1542
Author(s):  
Zhou Shi ◽  
Jun Li Guo ◽  
Wei Feng Su ◽  
Shuang Yang Zhang
Keyword(s):  
High Speed ◽  
Measured Data ◽  
Air Pressure ◽  
Turbulent Model ◽  
High Speed Train ◽  
Sound Barrier ◽  
Barrier Region ◽  
High Speed Trains ◽  
Train Speed ◽  
Volume Method

The special dynamic pulsating air pressure acting on the surface of sound barrier can be aroused by passing high speed train, making sound barrier structure and components prone to destruction and other issues. Based 3-D unsteady k-ε two-equation turbulent model, dynamic processes of high-speed trains passing the sound barrier region at different speeds and many factors are simulated and analyzed by using moving mesh finite volume method. The results of dynamic numerical calculated pulsating air pressure results and the effecting rule of various parameters were obtained, and compared with the measured data. It is showed that the air pressure value increases with the increasing train speed and the dynamic numerical calculated pulsating air pressure curves shape and effecting rule of parameters are all well matched with the measured data, but the air pressure value is slightly larger. At last, based on the results of numerical calculation, the addition of static air pressure value caused by high speed train is put forward.

Modelling and iterative learning control of internal pressure for high-speed trains under excitation of varying-amplitude tunnel pressure waves

2021 ◽  
pp. 095440972110460
Author(s):  
Zhiying He ◽  
Chunjun Chen ◽  
Dongwei Wang ◽  
Jia Hu ◽  
Lu Yang
Keyword(s):  
Iterative Learning Control ◽  
High Speed ◽  
Control Algorithm ◽  
Learning Control ◽  
Iterative Learning ◽  
Air Pressure ◽  
Pressure Waves ◽  
High Speed Trains ◽  
The Mathematical Model ◽  
Fixed Period

Traditional control algorithm of shutting down the air ducts for a fixed period is not applicable to take both the riding comfort and the air quality inside high-speed train carriages into account in long tunnels. Inspired by the morphological similarity of the tunnel pressure waves generated by the same train passes through the same tunnel, an upgraded iterative learning control algorithm for suppressing the air pressure variation excited by the quasi-periodic varying-amplitude tunnel pressure wave is developed. Firstly, the mathematical model of the control system is established, in which the air ducts, gaps and random interferences are considered. Then, the methodology of determining the goal in each iteration is formed, and the implementation of the iterative learning control algorithm is discussed. Finally, simulations of the algorithm are carried out. The simulation results show that in the upgraded iterative learning control algorithm, both the goal and the output of the air pressure inside the carriage will converge into a range determined by the amplitude and random interferences. By comparing with the traditional control algorithm, the upgraded iterative learning control algorithm is more adaptable to meet the needs of riding comfort.

Analysis of the aerodynamic pressure effect on the fatigue strength of the carbody of high-speed trains passing by each other in a tunnel

2018 ◽  
Vol 233 (8) ◽  
pp. 783-801
Author(s):  
Yaohui Lu ◽  
Dewen Zhang ◽  
Heyan Zheng ◽  
Chuan Lu ◽  
Tianli Chen ◽  
...  
Keyword(s):  
Finite Element ◽  
Fatigue Strength ◽  
Pressure Wave ◽  
High Speed ◽  
Aerodynamic Load ◽  
Aerodynamic Loads ◽  
Aerodynamic Pressure ◽  
High Speed Trains ◽  
Short Tunnel ◽  
The Impact

When two high-speed trains pass through a tunnel, the aerodynamic changes are more complex and drastic than in open air owing to the interference of the tunnel wall and the entry effect. The impact on the carbody fatigue strength is very significant in the fatigue reliability design of the carbody. In this paper, the sequential coupling method was used for the first time to study the effect of pressure waves on the fatigue strength in a large-scale and complex carbody structure. The computational fluid dynamics method was used to calculate and analyze the aerodynamic pressure wave of the intersection of the trains in a long and short tunnel. A full-scale finite element shell model of the carbody structure was established. Then, the time integration method was used to convert the transient pressure wave into the aerodynamic loads bearing by the side wall of the carbody. The inhomogeneous stress concentrations at the restraint points were eliminated by the inertial release method; moreover, a finite element analysis of the carbody was carried out under the combined aerodynamic and mechanical loads. The Goodman fatigue strength curve of the aluminum alloy carbody was drawn. The influence of the aerodynamic load on the fatigue strength of the vehicle body was analyzed and compared under the entry effect of the short tunnel. The results show that the aerodynamic load of the short tunnel has a significant impact on the fatigue strength of the carbody owing to the train's entry effect. The safety factor of the fatigue strength is 15% less than that of the long tunnel aerodynamic load. In this paper, computational fluid dynamics and finite element method were used to analyze and evaluate the impact of the pressure wave on the fatigue strength of the carbody, which is of great reference value in the structural design of the carbody subjected to complex aerodynamic loads.

scholarly journals Influence of tunnel length on the pressure wave generated by high-speed trains passing each other

2011 ◽  
Vol 55 (1) ◽  
pp. 255-263 ◽  
Author(s):  
YiWei Wang ◽  
GuoWei Yang ◽  
ChengGuang Huang ◽  
Wei Wang
Keyword(s):  
Pressure Wave ◽  
High Speed ◽  
Tunnel Length ◽  
High Speed Trains
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