Aerodynamic drag analysis of double-deck container vehicles with different structures

Liu, Hui; Tian, Huixin; Yang, Mingzhi

doi:10.1007/s11771-011-0838-8

Cited by 4 publications

(3 citation statements)

References 7 publications

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“…Following the work, the air is assumed to be viscous and incompressible, according to Anderson (2010). Owing to the benefit of reducing computing consumption, good stability for the solution and more accurate mimicking of the flow physics near the wall boundaries (Xie et al , 2014; Chitrakar et al , 2017; Kummitha et al , 2021), the standard k - ɛ turbulence model with enhanced wall treatment is adequate for modeling large-scale flow near trains or other complex structures under crosswind conditions (Li et al , 2011b; Liu and Zhang, 2013; Zhang et al , 2017). Furthermore, according to the previous investigations, a high agreement is shown between the measured data and the numerical results, when the standard k - ɛ model is used for simulating the turbulence transport under the wind-driven rain environment (Kubilay et al , 2013; Pettersson et al , 2016).…”

Section: Methodsmentioning

confidence: 99%

Influence of wind and rain environment on operational safety of intercity train running on the viaduct

Zeng

Huang

et al. 2023

HFF

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Purpose Based on the aerodynamic loads and dynamic performances of trains, this study aims to investigate the effect of crosswinds and raindrops on intercity trains operating on viaducts to ensure the safe operation of intercity railways in metropolitan areas. Design/methodology/approach An approach coupled with the Euler multiphase model as well as the standard k-ɛ turbulence model is used to investigate the coupled flow feature surrounding trains and viaducts, including airflow and raindrops, and the numerical results are validated with those of the wind tunnel test. Additionally, the train’s dynamic response and the operating safety region in different crosswind speeds and rainfall is investigated based on train’s aerodynamic loads and the train wheel–rail dynamics simulation. Findings The aerodynamic loads of trains at varying running speeds exhibit an increasing trend as the increase of wind speed and rainfall intensity. The motion of raindrop particles demonstrates a significant similarity with the airflow in wind and rain environments, as a result of the dominance of airflow and the supplementary impacts of droplets. As the train’s operating speed ranged between 120 and 200 km/h and within a rainfall range of 20–100 mm/h, the safe operating region of trains decreased by 0.56%–7.03%, compared with the no-rain condition (0 mm/h). Originality/value The impact of crosswind speeds and rainfall on the train’s aerodynamic safety is studied, including the flow feature of crosswind and different particle-sized raindrops around the train and viaduct, aerodynamic loads coefficients suffered by the intercity train as well as the operating safety region of intercity trains on the viaduct.

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Section: Methodsmentioning

confidence: 99%

Influence of wind and rain environment on operational safety of intercity train running on the viaduct

Zeng

Huang

et al. 2023

HFF

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“…Z. armatum 'YT-03' had lower symmetry and was more evolved. Some plant karyotypes can evolve from diploid to polyploid [49]. The evaluation of the five materials showed that the karyotype of varieties and cultivars of Z. armatum also potentially evolved from diploid to polyploid.…”

Section: Divergence Stages Of Five Z Armatum Materialsmentioning

confidence: 99%

Karyotype and Phylogenetic Relationship Analysis of Five Varieties and Cultivars of Zanthoxylum armatum based on Oligo-FISH

Lei

Gong

et al. 2023

Genes

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Green prickly ash (Zanthoxylum armatum) has edible and medicinal value and is an economically significant plant in many countries. Z. armatum has many cultivars and varieties with similar phenotypes that are difficult to distinguish via traditional methods. In this study, we utilized oligo-FISH to distinguish five varieties and cultivars of Z. armatum on the basis of three oligonucleotide probes of 5S rDNA, (AG3T3)3, and (GAA)6. Karyotype analysis of the five varieties and cultivars of Z. armatum showed that the Z. armatum ‘Tengjiao’ karyotype formula was 2n = 2x = 98m with karyotype type 1C and an arm ratio of 4.3237, including two pairs of 5S rDNA signals and five pairs of (GAA)6 signals. The karyotype formula of Z. armatum ‘Youkangtengjiao’ was 2n = 2x = 128m + 8sm with karyotype type 2B and an arm ratio of 3.5336, including three pairs of 5S rDNA signals and 17 pairs of (GAA)6 signals. The karyotype formula of Z. armatum var. novemfolius was 2n = 2x = 134m + 2sm with karyotype type 1C and an arm ratio of 5.5224, including two pairs of 5S rDNA signals and eight pairs of (GAA)6 signals. The karyotype formula of Z. armatum ‘YT-03’ was 2n = 2x = 2M + 128m + 4sm + 2st with karyotype type 2C and an arm ratio of 4.1829, including three pairs of 5S rDNA signals and nine pairs of (GAA)6 signals. The karyotype formula of Z. armatum ‘YT-06’ was 2n = 2x = 126m + 10sm with cytotype 2B and an arm ratio of 3.3011, including three pairs of 5S rDNA signals and two pairs of (GAA)6 signals. The five varieties and cultivars of Z. armatum had (AG3T3)3 signals on all chromosomes. The chromosomal symmetry of Z. armatum ‘Tengjiao’ was high, whereas the chromosomal symmetry of Z. armatum 'YT-03' was low, with the karyotypes of the five materials showing a trend toward polyploid evolution. The phylogenetic relationship between Z. armatum ‘Tengjiao’ and Z. armatum var. novemfolius was the closest, while that between Z. armatum ‘YT-03’ and Z. armatum ‘YT-06’ was closer than with Z. armatum ‘Youkangtengjiao’ according to oligo-FISH. The results provided a karyotype profile and a physical map that contributes to the distinction of varieties and cultivars of Z. armatum and provides strategies for distinguishing other cultivated species.

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“…Thus, a number of studies on freight train aerodynamics have been performed in the last decade. The numerical work of Li et al 4 and the experimental work of Watkins et al 5 has shown that there is a significant effect of the inter-car gaps on the aerodynamic performance of freight trains. They demonstrated that reducing the size of the inter-car gaps by placing smaller containers in-between existing containers can result in an up to 50% reduction in drag force.…”

Section: Introductionmentioning

confidence: 99%

Large eddy simulation of the flow around a train passing a stationary freight wagon

Liu

Hemida

Liu

2013

Proceedings of the Institution of Mechanical Engineers, Part F:

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In this paper, the effect of track spacing on the aerodynamic performance of a stationary double-stacked freight wagon passed by a high-speed passenger train is investigated using large eddy simulation (LES). The passenger train is a 1/20th scale model of an ICE2-shaped high-speed train and consists of nose, two coaches, inter-carriage gap and tail. Based on the speed and height of the passenger train, a flow Reynolds number of 2 Â 10 5 is used in the simulation studies. To isolate the effect of the mesh resolution computations are performed using three different meshes: coarse, medium and fine, consisting of 3.2 Â 10 6 , 6.9 Â 10 6 and 9.0 Â 10 6 nodes, respectively. The results are also validated with available experimental data and a good agreement is demonstrated. The aerodynamic loads on the freight containers and passenger train are obtained during a passing process. High side force values are generated on the freight containers when the passenger train approaches followed by a sudden reduction when the nose of the passenger train passes the freight wagons. There is also a reduction in the side force when the tail of the passenger train passes the freight wagon followed by a significant increase when the wake flow hits the freight wagon. Similar behavior is observed for the lift and drag coefficients. The effect of track spacing is investigated by performing simulations at three different track spacing values: 3.5, 4 and 4.5 m. The results show that a reduction in track spacing generally increases the aerodynamic forces on both the freight wagon and passenger train.

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Aerodynamic drag analysis of double-deck container vehicles with different structures

Cited by 4 publications

References 7 publications

Influence of wind and rain environment on operational safety of intercity train running on the viaduct

Influence of wind and rain environment on operational safety of intercity train running on the viaduct

Karyotype and Phylogenetic Relationship Analysis of Five Varieties and Cultivars of Zanthoxylum armatum based on Oligo-FISH

Large eddy simulation of the flow around a train passing a stationary freight wagon

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