The slow adoption of wagon roads on the Andes is an event widely noted. In this article we document the arrival of the first wagon road to the Andes: the Cambao wagon road connecting Bogotá to the ...Magdalena river valley in 1885. The road projects, its construction and traffic once it opened are presented and discussed using a variety of newly identified archival sources. It is argued that the historic and economic significance of this technological milestone was probably obscured by the all too soon expected arrival of railways.
The improvement in running safety and energy efficiency of railway freight transportation brings about great social and environmental benefits. This paper proposes a novel strategy for promoting the ...curving performance and reducing driving energy consumption by optimizing the position of the wagon's combined center of gravity (CCOG) when loading the cargo. The dynamics analysis of the vehicle model is conducted to reveal the effect of CCOG position. Based on the simulation results of the established and verified multibody dynamics model, the critical role that CCOG plays in driving energy consumption is investigated, which is proved to be different from the relationship between CCOG and the wheel unloading ratio. Furthermore, the optimal velocity of the specified loaded wagon is inferred to be about 26 m/s, and the small radius curve is demonstrated to be the worse working condition in most cases. Finally, the Pareto-optimal solutions of the CCOG position are derived, and their superiorities in running safety and energy conservation are validated. The proposed methodology which realizes the multi-objective optimization of the CCOG position can be applied to set other parameters of the railway wagon.
•High correlation between gravity center position and energy consumption is proved.•Optimal velocity for given wagon is about 26 m/s considering work of traction force.•Reduction of curve radius results in worse energy efficiency in most cases.•Derive Pareto-optimal solution with wheel unloading ratio and consumed driving energy.
In order to reduce the load of the open wagon body in operation, it has been proposed to use sandwich panels for sidewalls. The effectiveness of this solution was studied through the transverse ...loading of the open wagon body in operation. This included the building of a mathematical model that described the movement of a loaded open wagon during lateral oscillations. It has been found that the acceleration acting on the open wagon body is 4.1% lower than that acting on the typical design. The thickness of metal sheets forming a sandwich panel was determined by the Bubnov-Galerkin method. The strength of the open wagon body with sandwich-panel walls was calculated using the finite element method. The results of the calculation have made it possible to conclude that the stresses in the open wagon body are within the permissible limits and are lower than those acting in a typical design by 3.5%.
The results of the research will contribute to the scientific development database of innovative wagon designs with improved technical and economic characteristics, and increase the efficiency of railway transport.
Over the past 2 decades, the computational materials science community has made great advances in facilitating and supporting the development of new materials, particularly metallic alloys. While the ...materials community now has impactful computational tools, from Calculation of Phase Diagrams (CALPHAD) methods for computing phase diagrams, to density functional theory (DFT) for computing certain properties of individual phases, to Artificial Intelligence (AI) and Machine Learning (ML) to accelerate computational discoveries, experimental validation methods, in any high-throughput methodology, has been lacking. Metallic alloy synthesis has remained incredibly slow owing to traditional methods, such as arc-melting methods, remaining a one-off approach, which each individual sample requiring a separate sample preparation and characterization process, little if any of which is automated. To overcome these limitations, the High-Throughput Rapid Experimental Alloy Development (HT-READ) platform was developed. The HT-READ platform is a true paradigm change in the field of metallic alloy development, enabling fully automated synthesis and characterization of alloy samples in groups of 16 samples at once. The enabling feature of the HT-READ platform approach is the use of a single sample, with up to 16 individual alloy ‘spokes’ comprising a ‘wagon-wheel’ geometry. This geometry directly enables the automation of each of the characterization steps that can proceed without instrument operation by a trained engineer. In spite of the significant advantages of the HT-READ platform, the rate controlling step remains the physical weighing of the alloy powders used in the 3-D printing of the individual spokes of the ‘wagon-wheel’ sample. In the newly updated HT-READ platform, the powder handling and weighting process has now been automated using a ChemSpeed™ Doser, which can dispense up to 24 different powders, which might be needed to achieve the desired composition for each of the 16-spoke samples. With the Updated HT-READ platform, it is now possible to achieve truly high-throughput of metallic alloy development, with automated characterization across multiple instruments, from GDS, XRD, SEM-EDS, SEM-EBSD, microhardness, and nanoindentation.
In this paper, the intra-wagon channels at 60 and 300 GHz bands are characterized through measurement-validated ray-tracing (RT) simulations. To begin with, an in-house-developed three-dimensional RT ...simulator is calibrated and validated by a series of millimeter-wave and Terahertz channel measurements inside a high-speed train wagon. Then, the validated RT simulator is used to conduct extensive simulations with different transmitter (Tx) and receiver deployments. At low frequencies, the channel is strongly influenced by the line of sight (LOS), and therefore, is usually classified into LOS and non-LOS (NLOS) regions. However, the simulation results at 60 and 300 GHz bands show that the first-order reflection also imposes a significant impact on the channel characteristics. This motivates us to further classify the NLOS region into light-NLOS (L-NLOS) and deep-NLOS (D-NLOS) according to the existence of the first-order reflection. Through analyzing the area ratios of LOS, L-NLOS, and D-NLOS regions, we evaluate the Tx deployment strategies and suggest the optimum one. Based on RT simulation results, totally 12 cases (three propagation regions with two Tx deployments at two frequencies) are characterized in terms of path loss, shadow fading, root-mean-square delay spread, Rician K-factor, azimuth/elevation angular spread of arrival/departure, cross-polarization ratio, and their cross correlations. All these parameters are fed into the 3GPP-like quasi-deterministic radio channel generator (QuaDRiGa). The good agreement between QuaDRiGa and RT proves that the 13 tables provided in this paper effectively parameterize the intra-wagon scenario for the standard channel model family. These results provide valuable insights into the system design and evaluation for intra-wagon communications.
This review article offers an overview of technical and functional characteristics of mobile equipment that can support successful transportation of standard intermodal containers by rail. The ...following kinds of equipment are detailed: freight trains, container wagons, standard intermodal containers and mobile handling equipment. Freight trains are divided into wagon-load trains and unit trains, and the suitability of each train type for the large-scale transportation of standard intermodal containers is indicated. This is followed by explaining the two types of purpose-built container rail wagons and discussing the ten types of standard intermodal containers available. Finally, the functions and characteristics of contemporary types of mobile equipment that can effectively fulfil all the standard intermodal container handling requirements of modern intermodal transport operations are examined.
Given the constant demand for heavier, longer, faster, and more efficient rail freight vehicles, onboard fault detection systems appear as a good approach for enhanced railway asset exploitation. ...Real-time condition monitoring reduces inefficient preventive and reactive maintenance actions, decreases waste from replacing parts that still have a useful life, and improves availability and safety by real-time rolling stock diagnosis. There have been considerable advances in wayside monitoring applications, but these cannot achieve real-time continuous monitoring. With the price reduction and miniaturization trends of electronic devices, the cost of deploying wireless sensor networks onboard freight trains continues to become more feasible and accessible. On the other hand, the lack of onboard electric power availability on freight wagons appears as the major limitation for the implementation of these technologies. This paper reviews recent onboard condition monitoring sensors, systems, methods and techniques, aiming to define the present state of the art and its potential application for freight wagons without onboard electric power.
At present, the Russian railway network is experiencing a shortage of throughput capacity. At the same time, for a number of reasons, the direction of empty cars for loading is not always performed ...optimally, which leads to the presence of empty runs of cars of the same type and additional loading of limiting railway infrastructure facilities. In order to improve the rationality of empty wagon direction, it is proposed to calculate the optimal empty wagon directions at the stage of calculation of technical standards of operational work with their subsequent use in operational management and creation of economic incentives for their implementation.
Dynamics of railway freight vehicles Iwnicki, S.D.; Stichel, S.; Orlova, A. ...
Vehicle system dynamics,
07/2015, Letnik:
53, Številka:
7
Journal Article
Recenzirano
Odprti dostop
This paper summarises the historical development of railway freight vehicles and how vehicle designers have tackled the difficult challenges of producing running gear which can accommodate the very ...high tare to laden mass of typical freight wagons whilst maintaining stable running at the maximum required speed and good curving performance. The most common current freight bogies are described in detail and recent improvements in techniques used to simulate the dynamic behaviour of railway vehicles are summarised and examples of how these have been used to improve freight vehicle dynamic behaviour are included. A number of recent developments and innovative components and sub systems are outlined and finally two new developments are presented in more detail: the LEILA bogie and the SUSTRAIL bogie.
With the recent trend to require automotive aerodynamic testing in wind tunnels with rolling-road floors, this study investigates the impacts of the ground configuration on the aerodynamic ...characteristics of a generic estate-type vehicle – the DrivAer-Estate. This is based on a comparison between time-dependent computational predictions for two configurations: one with a stationary ground with stationary wheels, and another with a moving ground and rotating wheels. This study quantifies the time-averaged flow structures, wake dynamics, surface pressure distributions and aerodynamic loadings, and by comparing these for the two cases. This study determines the distinct flow features and the mechanism of how different ground simulations affect the aerodynamic characteristics. Predictions using an Improved Delayed Detached Eddy Simulation (IDDES) model are validated where possible against time-mean wind-tunnel measurements, providing confidence in the simulation results. Indeed, the results show that due to the distinct flow features generated by estate-type geometries, the ground configuration only locally alters the flow field in close proximity to the ground, and therefore its impact on the flow near the automobile surfaces and in the wake is limited. Regarding the aerodynamic loadings, only the underbody surface pressure is found to be sensitive to the ground simulation, which leads to a variation in the lift coefficient by a factor of approximately two. However, the impact on the drag prediction is minimal, with the two drag coefficient predictions within 3% of each other, and consistent within the range of values from previous wind-tunnel tests.
•The present study determines the effects of ground motion on the flow features around the vehicle, and hence improve the current understanding of why such a vehicle type is relatively less sensitive to ground motion.•This study additionally provides examples of methodology that can be applied to further analyse results for numerical work that investigate testing facility configurations, with most numerical studies utilising an unsteady solver.•Further detailed wake information on the full-scale DrivAer-Estate is provided, providing greater fidelity than might be feasible in experiments.
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