Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Effect of the ballast height on the slipstream and wake flow of high-speed train
https://orcid.org/0000-0002-6282-7615
https://orcid.org/0000-0003-0652-553X
https://orcid.org/0000-0002-7840-5185
Abstract The improved delayed detached-eddy simulation (IDDES) method based on the shear-stress transport (SST) κ-ω turbulence model was employed to investigate the ballast height influence on aerodynamic performance at Re = 9.12 × 106. Both time-averaged and instantaneous slipstreams and near-wake flow structures and associated slipstream velocity distributions are compared for four cases. Results reveal that the mean lift force coefficient decreases with increasing ballast height. At the Technical Specifications for Interoperability (TSI) trackside position, the maximum slipstream velocity with a ballast height of 1.825 m (Case 3) is 97.4%, 15.6% and 11.7% lower than with a ballast height of 0 m (Case 1), 0.825 m (Case 2) and 2.825 m (Case 4), respectively. The TSI values in Case 3 at both the trackside and platform positions are the lowest. In the wake region, increasing the ballast height greatly constrains the outward and downward movements of vortices. The slipstream velocity in the wake region in Case 3 is the lowest among all cases. In this study, we found that Case 3 greatly decreases the slipstream velocity around the train and improves the flow structure in the wake region, which reduces the risk to workers and equipment along the railway.
Highlights The CFD results were validated with wind tunnel experiment and found good agreement. IDDES k-w turbulence model is used to model the detailed flow field structure. The effect of height of ballast on the slipstream and wake dynamics of train is investigated.
Effect of the ballast height on the slipstream and wake flow of high-speed train
https://orcid.org/0000-0002-6282-7615
https://orcid.org/0000-0003-0652-553X
https://orcid.org/0000-0002-7840-5185
Abstract The improved delayed detached-eddy simulation (IDDES) method based on the shear-stress transport (SST) κ-ω turbulence model was employed to investigate the ballast height influence on aerodynamic performance at Re = 9.12 × 106. Both time-averaged and instantaneous slipstreams and near-wake flow structures and associated slipstream velocity distributions are compared for four cases. Results reveal that the mean lift force coefficient decreases with increasing ballast height. At the Technical Specifications for Interoperability (TSI) trackside position, the maximum slipstream velocity with a ballast height of 1.825 m (Case 3) is 97.4%, 15.6% and 11.7% lower than with a ballast height of 0 m (Case 1), 0.825 m (Case 2) and 2.825 m (Case 4), respectively. The TSI values in Case 3 at both the trackside and platform positions are the lowest. In the wake region, increasing the ballast height greatly constrains the outward and downward movements of vortices. The slipstream velocity in the wake region in Case 3 is the lowest among all cases. In this study, we found that Case 3 greatly decreases the slipstream velocity around the train and improves the flow structure in the wake region, which reduces the risk to workers and equipment along the railway.
Highlights The CFD results were validated with wind tunnel experiment and found good agreement. IDDES k-w turbulence model is used to model the detailed flow field structure. The effect of height of ballast on the slipstream and wake dynamics of train is investigated.
Effect of the ballast height on the slipstream and wake flow of high-speed train
https://orcid.org/0000-0002-6282-7615
https://orcid.org/0000-0003-0652-553X
https://orcid.org/0000-0002-7840-5185
Abstract The improved delayed detached-eddy simulation (IDDES) method based on the shear-stress transport (SST) κ-ω turbulence model was employed to investigate the ballast height influence on aerodynamic performance at Re = 9.12 × 106. Both time-averaged and instantaneous slipstreams and near-wake flow structures and associated slipstream velocity distributions are compared for four cases. Results reveal that the mean lift force coefficient decreases with increasing ballast height. At the Technical Specifications for Interoperability (TSI) trackside position, the maximum slipstream velocity with a ballast height of 1.825 m (Case 3) is 97.4%, 15.6% and 11.7% lower than with a ballast height of 0 m (Case 1), 0.825 m (Case 2) and 2.825 m (Case 4), respectively. The TSI values in Case 3 at both the trackside and platform positions are the lowest. In the wake region, increasing the ballast height greatly constrains the outward and downward movements of vortices. The slipstream velocity in the wake region in Case 3 is the lowest among all cases. In this study, we found that Case 3 greatly decreases the slipstream velocity around the train and improves the flow structure in the wake region, which reduces the risk to workers and equipment along the railway.
Highlights The CFD results were validated with wind tunnel experiment and found good agreement. IDDES k-w turbulence model is used to model the detailed flow field structure. The effect of height of ballast on the slipstream and wake dynamics of train is investigated.
Effect of the ballast height on the slipstream and wake flow of high-speed train
Liang, Xi-feng (Autor:in) / Zhang, Xin (Autor:in) / Chen, Guang (Autor:in) / Li, Xiao-bai (Autor:in)
30.09.2020
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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