scholarly journals Research@ZaB: FDS Features for Pressure Loading Assessment Within the Context of the Train-Tunnel Model Development

2021 ◽  
Author(s):  
Aliaksei Patsekha ◽  
Robert Galler
Keyword(s):  
High Speed ◽  
Safety Assessment ◽  
Model Development ◽  
Operational Reliability ◽  
High Speed Train ◽  
Cfd Model ◽  
Pressure Loading ◽  
Helpful Tool ◽  
Tunnel Model ◽  
Tunnel System

AbstractThe CFD model of the train-tunnel system, previously developed on proven analytical dependencies, is improved by the introduction of a tunnel cross-passage and the consideration of surface roughness. These additions bring the simulation setup closer to real conditions allowing to explore the FDS features in the evaluation of the aerodynamic effects occurring in a tunnel. Pressure and velocity patterns are obtained for the resulting model of a high-speed train in a tunnel with a cross-passage. The maximal and minimal pressure levels for the tunnel and the cross-passage spans are calculated to provide the data for the design phase and safety assessment. The approach to determine the most loaded surfaces of the tunnel and its inner structures, e.g. escape doors, for an estimation of their operational reliability is discussed. The study shows that the FDS software can be a helpful tool in assessing scenarios where the train-tunnel interaction is reviewed, though its applicable capabilities and set of features are largely dependent on the tasks to solve and need to be accurately adjusted.

scholarly journals Operational Safety Assessment of a High-speed Train Exposed to the Strong Gust Wind

2020 ◽  
Vol 16 (1) ◽  
pp. 55-66
Author(s):  
Mengge Yu ◽  
Zhenkuan Pan ◽  
Jiali Liu ◽  
Haiqing Li
Keyword(s):  
High Speed ◽  
Safety Assessment ◽  
High Speed Train ◽  
Operational Safety

Multi-Level Materials Service Safety Assessment System

2012 ◽  
Vol 572 ◽  
pp. 410-414
Author(s):  
Yi Bo Ai ◽  
Hao Cui ◽  
Wei Dong Zhang
Keyword(s):  
High Speed ◽  
Safety Assessment ◽  
Data Transfer ◽  
Research Result ◽  
Assessment System ◽  
High Speed Train ◽  
Security Issues ◽  
New Energy ◽  
Multi Level ◽  
Energy Equipment

With a number of major projects put into operation, such as high-speed train, marine platforms and new energy equipment, the service security issues for these projects have got more and more community-wide concern and become a hot topic in the recent study. Such systems' features are divided into more levels, the imbalance of existing data, and the longer service time. To resolve such service security issues, a variety of new methods such as multi-level modeling, data transfer between levels, and data balance method, must be introduced in the traditional reliability methods. In this paper, a multi-level materials service safety assessment system has been proposed, and a data processing method and the data transfer rules between levels have also been proposed based on Bayesian inference method and hybrid testing. The research result can be widely used in aerospace, high-speed train, new energy equipment and other fields needing service safety assessment.

Two-Phase Short Circuit in the Power Grid Powered by a Transformer with a Y/Δ-11 Winding Connection

2020 ◽  
pp. 25-30
Author(s):  
Aleksandr S. Serebryakov ◽  
Vladimir L. Osokin ◽  
Sergey A. Kapustkin
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
Relay Protection ◽  
Electric Circuit ◽  
Operational Reliability ◽  
Research Purpose ◽  
Industrial Complex ◽  
Two Phase ◽  
Short Circuit Currents ◽  
Secondary Winding

The article describes main provisions and relations for calculating short-circuit currents and phase currents in a three-phase traction transformer with a star-triangle-11 connection of windings, which feeds two single-phase loads in AC traction networks with a nominal voltage of 25 kilovolts. These transformers provide power to the enterprises of the agro-industrial complex located along the railway line. (Research purpose) The research purpose is in substantiating theoretical equations for digital intelligent relay protection in two-phase short circuits. (Materials and methods) It was found that since the sum of instantaneous currents in each phase is zero, each phase of the transformer works independently. We found that this significantly simplifies the task of analyzing processes with a two-phase short circuit. In this case, the problem of calculating short-circuit currents in the traction network can be simplified by reducing it to the calculation of an ordinary electric circuit with three unknown currents. (Results and discussion) The article describes equations for calculating short-circuit resistances for one phase of the transformer when connecting the secondary winding as a star or a triangle. The currents in the phases of the transformer winding at short circuit for the star-triangle-11 and star-star-with-ground schemes are compared. It was found that when calculating short-circuit currents, there is no need to convert the secondary winding of the traction transformer from a triangle to a star. (Conclusions) It was found that the results of the research can be used in the transition of relay protection systems from electromagnetic relays to modern high-speed digital devices, which will increase the operational reliability of power supply systems for traction and non-traction power consumers.

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