Combined Train Research Articles

Dynamic Load Modelling within Combined Transport Trains during Transportation on a Railway Ferry

The development of foreign economic activity of the Eurasian states led to the introduction of rail and ferry transportation. It is important to note that the current normative documentation does not fully cover the issues of transporting combined trains by sea. This can lead to a violation of the traffic safety of both the railway ferry and the transport of containers as part of combined trains by sea. In this connection, we investigated the dynamic loading of a container as part of a combined train when transported by a railway ferry. To ensure the stability of the container relative to the frame, we suggested an improvement of the load-bearing structure of a flat wagon. Additionally, we suggested the use of a viscous linkage between containers with the aim of reducing their dynamic load. To justify the suggested solutions, we carried out a mathematical modelling of the container dynamic load. The calculation was performed in MathCad. Due to the fact that the container has its own degree of freedom when transported by sea, the accelerations were separately determined for the supporting structure of the flat wagon and for the container. We found that the total amount of acceleration that acted on the container was 3.57 m/s2 (0.36 g) and on the load-bearing structure of the wagon was 2.47 m/s2 (0.25 g) which were, respectively, 38% and 23% less than the acceleration values in the typical scheme of their interaction. To determine the fields of acceleration distribution relative to the load-bearing structure of a flat wagon with containers, we carried out computer modelling of their dynamic load. The maximum percentage of discrepancy between the accelerations obtained by mathematical and computer modelling was 17.7%. The study will contribute to the creation of recommendations for the safe transport of combined trains by sea, as well as to increasing the efficiency of combined transport through international transport corridors.

Determination of dynamic load features of tank containers when transported by rail ferry

Simulation of the dynamic load of the tank container when transported as part of a combined train on a rail ferry is carried out. Mathematical models taking into account possible interactions of tank containers with the frame of flat cars are developed. Calculations are made for the tank container of 1CS type size placed on the 13-4012M flat car. It is taken into account that the transportation of the tank container is carried out on the “Geroi Shipki” type rail ferry by the Black Sea. It is found that the greatest acceleration acts on the tank container in case of displacement of the flat car relative to the deck and the tank container relative to the frame. The total value of acceleration is about 0.9g.The stability of the tank container when transported by rail ferry is investigated. Permissible roll angles of the rail ferry that ensure the stability of the tank container relative to the flat car frame are calculated.Computer simulation of the dynamic load of the tank container when transported by rail ferry is carried out. The calculation is made in the CosmosWorks software environment. The fields and numerical values of the accelerations acting on the tank container are determined. The developed models are verified by the F-criterion.The research will help to provide safety and to make recommendations on sea transportation of combined trains by rail ferries, as well as to design tank containers with improved technical-economic, strength and environmental characteristics.

Sequential electrocoagulation-electrooxidation for virus mitigation in drinking water

Electrochemical water treatment is a promising alternative for small-scale and remote water systems that lack operational capacity or convenient access to reagents for chemical coagulation and disinfection. In this study, the mitigation of viruses was investigated using electrocoagulation as a pretreatment prior to electrooxidation treatment using boron-doped diamond electrodes. This research is the first to investigate a sequential electrocoagulation-electrooxidation treatment system for virus removal. Bench-scale, batch reactors were used to evaluate mitigation of viruses in variable water quality via: a) electrooxidation, and b) a sequential electrocoagulation-electrooxidation treatment train. Electrooxidation of two bacteriophages, MS2 and ΦX174, was inhibited by natural organic matter and turbidity, indicating the probable need for pretreatment. However, the electrocoagulation-electrooxidation treatment train was beneficial only in the model surface waters employed. In model groundwaters, electrocoagulation alone was as good or better than the combined electrocoagulation-electrooxidation treatment train. Reduction of human echovirus was significantly lower than one or both bacteriophages in all model waters, though bacteriophage ΦX174 was a more representative surrogate than MS2 in the presence of natural organic matter and turbidity. Compared to conventional treatment by ferric salt coagulant and free chlorine disinfection, the electrocoagulation-electrooxidation system was less effective in model surface waters but more effective in model groundwaters. Sequential electrocoagulation-electrooxidation was beneficial for some applications, though practical considerations may currently outweigh the benefits.

The Modelling of Middle Locomotives and Their Couplers of Heavy Haul Train and Dynamical Simulations under Pressing Coupler Force

To study the dynamic performance of middle locomotives and their couplers of 20,000t heavy haul combined train under pressing coupler force, the longitudinal dynamic characteristics of train’s electric braking, cyclic braking and emergency braking on straight track were calculated with the longitudinal train dynamics (LTD) simulation package TDEAS, the coupler force of middle locomotives were obtained and sent to multi-body system (MBS) model of train established in package SIMPACK, and then the dynamic behaviour of middle locomotives and their couplers under pressing coupler force were studied. The results show that under the pressing force in straight track, the vertical dynamic performance of locomotive will be influenced in certain degree, the guiding wheelsets will upload while the rear wheelsets unload, the more the pressing force is, the greater the upload and unload will be. There is less influence on lateral dynamic under straight track condition.

Influence of Draft Gear Modeling on Dynamics Simulation for Heavy‐Haul Train

In order to study the impedance characteristics of the frictional draft gear, MT‐2 draft gear is studied, and its mechanical properties are analyzed firstly. Then, the mathematical models of two common draft gears are established based on the data collected from the vehicle impact test, and the effects of the two modeling methods on the simulation results are compared through the shunting impact test and the bench test simulation. Researches show that, under various experimental conditions, the simulated draft gear characteristic curve of the lookup table model moves along a fixed trajectory regardless of the change rate of the draft gear stroke, while simulation results of the wedge‐spring model depend on the change rate of the draft gear stroke and are more consistent with the experimental results, reflecting the dynamic characteristics of the draft gear and suggesting better adaptability and wider application. Finally, the “1 + 1” grouped 20,000‐ton heavy‐haul combined train model is established, with its draft gear characteristics under the full‐braking condition on flat straight track analyzed. Calculation results and test results of the lookup table model and the wedge‐spring model are compared, indicating that using the wedge‐spring model to calculate the longitudinal dynamics performance is more accurate. The influence of the modeling on the longitudinal impulse simulation of the train after air braking is also studied, revealing that the variation trends of the coupler force curves of two models are basically the same, but the amplitude and frequency of the longitudinal impulse are different.

Influence of bulk cargo pressure on container stability during transportation by railroad ferry

Efforts of bulk cargo expansion on the walls of the container during transportation as a part of a combined train by rail ferry are determined. The Coulomb method with Sinelnikov correction was used as the calculation. Studies have been conducted on a grain loaded 1C container. It is considered that the transportation of the container is carried out on the railway ferry "Heroes of Shipka", the waters of the Black Sea. Dynamic loading, which acts on the container during fluctuations of the railway ferry in the conditions of onboard swing, is taken into account in determining the forces of decomposition. At the same time three schemes of movements of the container placed on the wagon platform during fluctuations of the railway ferry are considered: absence of movements of the wagon platform and containers relative to the starting position during the fluctuations of the railway ferry (I scheme); the presence of displacements of the wagon-platform during the fluctuations of the railway ferry, taking into account the immobility of the containers relative to the frame of the wagon-platform (scheme II); the presence of displacement of the platform wagon relative to the deck and containers relative to the frame of the wagon platform (scheme III). The results obtained are taken into account in determining the stability of the container relative to the frame of the wagon platform. The angles of roll of the ferry at which the stability of the container relative to the frame of the wagon platform are determined. It is established that the stability of the container relative to the frame of the wagon platform is provided at the angles of roll of the ferry – up to 10° (I scheme), up to 8° – (II scheme), up to 6° (III scheme). This necessitates the improvement of the interaction scheme of the container with the wagon platform to ensure the safety of carriage by rail. The researches carried out will help to increase the safety of transportation of containers as part of combined trains by rail ferries.

Simulation analysis on the coupler behaviour and its influence on the braking safety of locomotive

ABSTRACTIn order to simulate the runtime behaviour of coupler and buffer systems accurately, the dynamic model was improved by adopting the polygonal contact model. And the reliability of the friction phenomenon in flat-pin coupler’s tail and the connecting constraint between coupler heads were verified. Then the detailed model which fully considered the dynamic characteristics of middle locomotive and its adjacent wagons was incorporated into the simplified longitudinal dynamic model of combined heavy-haul train. The dynamic response of coupler and its influence on the running safety of locomotive under flat straight line emergency braking condition and long steep grade cycle braking condition were simulated respectively. According to the simulation results, the following suggestions were proposed: flat-pin coupler is more suitable for heavy-haul locomotive, but the inspection work on the friction surface of coupler tail needs to be strengthened; and the vertical anti-off stopping device should be added to avoid the occurrence of decoupling accidents.

Simulation of loads for a tank container included in combined trains transported by train ferry

The article deals with the research into dynamic loading of a tank container of improved structure included in a combined train transported by train ferry. In order to define accelerations as a dynamic loading component on the tank container under train ferry vibrations, a mathematical model was built with the method of Lagrange multipliers of the second kind. The research considered angular displacements of the train ferry relative to the longitudinal axle (careen), as the maximum loading of the carrying structure of a flat wagon with tank containers, and also their stability relative to the deck. It was considered that the flat wagon was rigidly fixed relative to the deck, and the tank wagons – relative to the fitting stops and did not have their own degree of freedom under train ferry vibrations, i.e. the only fluid cargo, limited by the tank walls, could vibrate. The mathematical model was solved by the Runge–Kutta method in the MathCad environment. The maximum acceleration on the normal position of the tank container under train ferry vibrations was defined. The general acceleration value also considered the horizontal component of the free fall acceleration conditioned by the train ferry’s angle of heel. The results obtained were considered in the capacity calculation of a tank wagon with the Finite Element Method in the CosmosWorks environment. The calculation showed that the maximum equivalent loads for the improved carrying structure of a tank wagon did not exceed the admissible ones. The results of the research conducted can be applied in designing new generation tank containers; they may also promote higher efficiency of the international combined transportation.

К вопросу взаимодействия подвижного состава и геометрических параметров трассы высокоскоростных железнодорожных магистралей

Objective: Due to the lack of global experience of holding on one track high-speed passenger trains (moving at a speed up to 400 km/h), high-speed passenger trains (moving at a speed up to 250 km/h) and special freight trains (accelerating to a speed of more than 200 km/h), the only possible way of studying the influence of a train on a track is computer simulation modeling. The analysis of the existing computer programs was carried out and the most effective programme for the solution of combined train movement was selected. Methods: Simulation modeling was applied. On the basis of the obtained model the possibility of “Universal mechanism” software practical application was considered. Results: A test simulation model of a high-speed train carriage was developed in “Universal mechanism” software application. Preliminary results showed the possibility of its usage for the study of a high-speed train and track interaction. Practical importance: Modern computer technologies make it possible to solve the tasks of dynamic interaction with a high degree of accuracy. Among the variety of software used for the study of dynamic behavior of a railway vehicle in Russia, “Universal mechanism” software application is of wide popularity and may be used for the study of dynamic behavior of different types of trains on railway tracks of different plans and profiles.

Analysis of longitudinal forces of coupler devices in emergency braking process for heavy haul trains

To reduce the longitudinal coupler forces of heavy haul trains and improve the running safety, the velocity method and New-mark method were used for the coupler simulation and numerical integration, and a numerical model on the longitudinal dynamics of heavy haul trains was established. Validation was performed against the experimental data. Using this model, the emergency braking process for a combined marshalling heavy haul train was investigated to obtain the distributions of the longitudinal compressive forces and strokes of coupler devices. Then, the influences of the initial braking velocity, the synchronization time of master and slave locomotives, the coupler stiffness and the vibrator mass on the longitudinal forces and strokes were analyzed. The results show that it should be avoided that the emergency braking starts at a low initial speed. Keeping synchronism between master locomotive and slave locomotives effectively helps to reduce the longitudinal forces. Reducing the coupler stiffness appropriately and adding rigid arm connections, the longitudinal vibration frequency can be brought down and the longitudinal forces will be decreased, which improves the running safety of heavy haul trains. All of these research results can provide a reference for the operation and development of heavy haul trains.

Dynamic performance of heavy-haul combined train applying emergency braking on straight line

A heavy-haul train-track coupled model is developed. Taking the emergency braking of the 2×104 t combined train as example, the train longitudinal impulse, the coupler dynamic behaviors and wheel-rail interactions of vehicles distributing in the different positions are analyzed. The results indicate that under the coupler compressing forces, the couplers of middle locomotives may tilt to the free swing limits, which induces the unidirectional tilt of their connected wagon couplers. Consequently, the coupler longitudinal forces produce the lateral components, and then affect the wheel−rail dynamic interaction. The performance of the middle locomotive and their neighboring freight wagons deteriorate significantly, becoming the most dangerous parts in the combined train. The wagons disconnecting with the locomotives can basically keep their couplers to stabilize in the centering positions, even though the maximum coupler longitudinal force acts on it. And its corresponding running safety also has little changes.

Torsional Robustness of the Combined Cycle Power Train Arrangement: Application of Statistical Methods to Accelerate Shaft-Line Design Cycles

This article presents the application of statistical methods to guide the rotordynamic design of a turbogenerator shaft-line. One of the basic requirements is all shaft components must survive the event of a short circuit at the terminals of the generator. This is typically assessed via a transient response simulation of the complete machine train (including generator's electrical model) to check the calculated response torque against the allowable value. With an increasing demand of a shorter design cycle and competition in performance, cost, footprint, and safety, the probabilistic approach is starting to play an important role in the power train design process. The main challenge arises with the size of the design space and complexity of its mapping onto multiple objective functions and criteria which are defined for different machines. In this paper, the authors give an example demonstrating the use of statistical methods to explore (design of experiment (DoE)) and understand (surface response methods) the design space of the combined cycle power train with respect to the typically most severe constraint (fault torque torsional response), which leads to a quicker definition of a turbogenerator's arrangement. Further statistical analyses are carried out to understand the robustness of the chosen design against future modifications as well as parameters' uncertainties.

A multiphase optimal control method for multi-train control and scheduling on railway lines

We consider a combined train control and scheduling problem involving multiple trains in a railway line with a predetermined departure/arrival sequence of the trains at stations and meeting points along the line. The problem is formulated as a multiphase optimal control problem while incorporating complex train running conditions (including undulating track, variable speed restrictions, running resistances, speed-dependent maximum tractive/braking forces) and practical train operation constraints on departure/arrival/running/dwell times. Two case studies are conducted. The first case illustrates the control and scheduling problem of two trains in a small artificial network with three nodes, where one train follows and overtakes the other. The second case optimises the control and timetable of a single train in a subway line. The case studies demonstrate that the proposed framework can provide an effective approach in solving the combined train scheduling and control problem for reducing energy consumption in railway operations.

Investigation of Diesel Hybrid systems for fuel oil reduction in slow speed ocean going ships

The volatile world economy and the adoption of stricter emission policies from the European Union and the International Maritime Organisation greatly affect the shipping industry. This paper is focused on the potential of Diesel Hybrid power systems to increase fuel efficiency for ocean going slow speed ships. Alternatives in on-board energy generation, management and storage strategies are investigated. The mathematical implementation and simulation of the power train components is demonstrated using a systematic approach. Vessel operational profiles were incorporated to the power train optimisation problem. The optimisation scenarios were run using a modified marine power systems version of the Equivalent Cost Minimisation Strategy. The results indicate fuel savings for auxiliary loads as a result of the absence of conversion losses. For the main Diesel hybrid propulsion, the system is deemed infeasible. Nevertheless, for the combined Hybrid power train, the savings are achieved by proper handling of the originated energy from the Main and Auxiliary engines.

Mixed-Integer Programming for Railway Capacity Analysis and Cyclic, Combined Train Timetabling and Platforming

We present the literature’s first mixed-integer linear programming model of a cyclic, combined train timetabling and platforming problem. The model’s objectives are to minimize (1) the cycle length and (2) the total journey time of all trains dispatched during one cycle. The model falls outside the framework of the well-known periodic event scheduling problem and explicitly considers the minimization of cycle length using linear constraints and a linear objective function. We define the model, propose methods for obtaining bounds on the optimal objective value, and describe preprocessing techniques for reducing the number of variables and constraints. Numerous life-size problem instances are solved to optimality using IBM ILOG CPLEX. Results show the model’s effectiveness in pursuing objectives 1 and 2, the benefits of deciding the cyclic train order versus assuming a given order, and the model’s ability to calculate railway capacity without bias.

Microscopic charge carrier lifetime in silicon from a transient approach

We present an experimental approach to determine the charge carrier lifetime in silicon based on the measured transient decay of the emitted photoluminescence intensity, requiring only a crystal volume of 50 μm in diameter. This becomes feasible by a combination of the time correlated single photon counting technique and confocal microscopy. Using combined pulsed and pulse train laser excitation, we obtain a self-consistent charge carrier lifetime in a high dynamic range from 100 ns to ms and an injection range from 1010 cm−3 to high injection densities. An iterative data evaluation routine incorporates all effects induced by the spatially non-homogeneous charge carrier generation.

Costs of Advanced Treatment in Water Reclamation

The additional removal of trace organic contaminants (TOrCs) provided by advanced water and wastewater treatment inevitably requires additional financial costs, which must be estimated to support utility planning and compare alternatives. This study presents conceptual-level (Class 4) capital and annual operations and maintenance (O&M) cost curve equations to aid evaluations of advanced treatment trains for water reuse. The cost curve equations are broadly applicable to the water reuse community, particularly those interested in ozone-based treatment trains. Unit processes include microfiltration or ultrafiltration membranes (MF/UF), nanofiltration or reverse osmosis membranes (NF/RO), ozone (with or without hydrogen peroxide, H2O2), ultraviolet (UV) treatment with H2O2 (UV/H2O2), and biological activated carbon (BAC); all cost curves are for a unit process and can be added together to obtain costs for a combined treatment train. The cost curves indicate that at all plant capacities (1 to 500 MGD), membrane treatment (e.g., MF or RO) represents the highest cost unit process, ozone the least, and BAC or UV/H2O2 fall in between. Additionally, the relationship between ozone dose and TOrC removal is discussed with a demonstration of how costs change with increasing ozone dose to achieve desired TOrC destruction.

Active Fault Tolerant Control of a Wind Turbine via Fuzzy MPC and Moving Horizon Estimation

This paper proposes an approach to active fault tolerant control (AFTC) of a variable-speed wind turbine subject to actuator faults. The actuator faults in the turbine pitch system and generator system are considered in this work. Takagi-Sugeno (T-S) fuzzy modeling of the combined driver train, pitch and generator systems is proposed to account for nonlinearities in the dynamics. Moving horizon estimation (MHE) based on T-S fuzzy modeling is proposed as the actuator fault estimation unit. Model predictive control (MPC) based on T-S fuzzy modeling is used in the design of the AFTC unit in which the predictive controller compensates the actuator faults and takes into account the model nonlinearity and turbine system constraints. A T-S fuzzy observer is used to estimate system states and thus an output feedback strategy of an observer-based predictive controller is formed.

Research on Transportation Organization Schemes of Jinzhongnan Railway Passage

The paper analyzed basics of Jinzhongnan railway passage. Conclude that the passage belongs to Half-Open Heavy-haul railway and the transport organization is special by analyzing Heavy-haul railway mode. Analyze the operation of combined train in receiving-departure track of 1700m effective length couldnt match receiving-departure track of 1050m effective length on existed lines. On the basis of analyzing transport demand and transport capacity, suggest to increase the length of receiving-departure track of some stations to 2100m. And obtain transportation organization schemes of Jinzhongnan passage by integer programming.

Design of Polarization De-Multiplexer and PMD Compensator for 112 Gb/s Direct-Detect PDM RZ-DQPSK Systems

The design of a polarization de-multiplexer and a polarization mode dispersion compensator (PMDC) for direct-detect polarization division multiplexed (PDM) return-to-zero differential quadrature phase shift keying (RZ-DQPSK) systems are studied in detail. The impact of polarization dependent loss is studied in polarization de-multiplexers with different error detection configurations for both bit-aligned and bit-interleaved PDM systems. The level of the clock frequency of the combined pulse train of the two polarizations is proposed as the error signal for the PMDC. It enables the PMDC to work in the cancellation mode. Two separate control loops are proposed for the polarization de-multiplexer and the PMDC to allow them to work independently. The DGD tolerances for the one-stage and two-stage PMDC are measured and discussed. Finally the glitch problem in the polarization tuning algorithm is studied. An advanced dithering algorithm and the corresponding architecture of the polarization controller are proposed to solve the glitch problem.