Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
On the influence of Reynolds number and ground conditions on the scaling of the aerodynamic drag of trains
https://orcid.org/0000-0002-8674-9332
Abstract The present study examines the possibilities of transferring drag measurement results on reduced-scale train models to the respective full-scale vehicle. A comprehensive experimental and numerical study of the boundary layer and skin friction along trains is performed, focusing on Reynolds number effects. The data are supplemented by an extensive literature study and compared with different approaches from flat plate theory. Good agreement can be found when using the appropriate empiric coefficients and boundary conditions. Simultaneously, the difficulties in determining the skin friction drag of trains due to three-dimensional effects and surface roughness become apparent. The ground simulation analysis, including the effects of ground roughness due to ballast and sleepers, reveals a significant effect of the ground conditions on the vehicle’s aerodynamic drag. Additionally, the effects of elements mounted on the train roof are investigated for different upstream flow conditions. Finally, a scaling method is proposed to transfer drag results from model-scale to full-scale trains based on the findings.
Highlights Trackbed roughnesses strongly influence the underbody friction of trains. Boundary layer profiles of trains can be approximated by the flat plate theory. Reynolds number effects in train aerodynamics occur both at model and full-scale. Roof elements can strongly alter the drag and wake of the train.
On the influence of Reynolds number and ground conditions on the scaling of the aerodynamic drag of trains
https://orcid.org/0000-0002-8674-9332
Abstract The present study examines the possibilities of transferring drag measurement results on reduced-scale train models to the respective full-scale vehicle. A comprehensive experimental and numerical study of the boundary layer and skin friction along trains is performed, focusing on Reynolds number effects. The data are supplemented by an extensive literature study and compared with different approaches from flat plate theory. Good agreement can be found when using the appropriate empiric coefficients and boundary conditions. Simultaneously, the difficulties in determining the skin friction drag of trains due to three-dimensional effects and surface roughness become apparent. The ground simulation analysis, including the effects of ground roughness due to ballast and sleepers, reveals a significant effect of the ground conditions on the vehicle’s aerodynamic drag. Additionally, the effects of elements mounted on the train roof are investigated for different upstream flow conditions. Finally, a scaling method is proposed to transfer drag results from model-scale to full-scale trains based on the findings.
Highlights Trackbed roughnesses strongly influence the underbody friction of trains. Boundary layer profiles of trains can be approximated by the flat plate theory. Reynolds number effects in train aerodynamics occur both at model and full-scale. Roof elements can strongly alter the drag and wake of the train.
On the influence of Reynolds number and ground conditions on the scaling of the aerodynamic drag of trains
https://orcid.org/0000-0002-8674-9332
Abstract The present study examines the possibilities of transferring drag measurement results on reduced-scale train models to the respective full-scale vehicle. A comprehensive experimental and numerical study of the boundary layer and skin friction along trains is performed, focusing on Reynolds number effects. The data are supplemented by an extensive literature study and compared with different approaches from flat plate theory. Good agreement can be found when using the appropriate empiric coefficients and boundary conditions. Simultaneously, the difficulties in determining the skin friction drag of trains due to three-dimensional effects and surface roughness become apparent. The ground simulation analysis, including the effects of ground roughness due to ballast and sleepers, reveals a significant effect of the ground conditions on the vehicle’s aerodynamic drag. Additionally, the effects of elements mounted on the train roof are investigated for different upstream flow conditions. Finally, a scaling method is proposed to transfer drag results from model-scale to full-scale trains based on the findings.
Highlights Trackbed roughnesses strongly influence the underbody friction of trains. Boundary layer profiles of trains can be approximated by the flat plate theory. Reynolds number effects in train aerodynamics occur both at model and full-scale. Roof elements can strongly alter the drag and wake of the train.
On the influence of Reynolds number and ground conditions on the scaling of the aerodynamic drag of trains
Tschepe, Jonathan (Autor:in) / Nayeri, Christian Navid (Autor:in) / Paschereit, Christian Oliver (Autor:in)
06.03.2021
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Drag , Friction , Boundary layer , Reynolds number , Trains , Aerodynamics
Aerodynamic drag reduction of goods trains
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The aerodynamic drag of high speed trains
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High Reynolds number wind tunnel experiments on trains
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High Reynolds number wind tunnel experiments on trains
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