A 2D computational parametric analysis of the sheltering effect of fences on a railway vehicle standing on a bridge and experiencing crosswinds

Sesma, Ignacio and Larraona, Gorka S. and Vinolas, Jordi and Rivas, Alejandro and Avila Sanchez, Sergio (2013). A 2D computational parametric analysis of the sheltering effect of fences on a railway vehicle standing on a bridge and experiencing crosswinds. "Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail And Rapid Transit" ; pp. 1-16. ISSN 0954-4097. https://doi.org/10.1177/0954409713504395.

Description

Title: A 2D computational parametric analysis of the sheltering effect of fences on a railway vehicle standing on a bridge and experiencing crosswinds
Author/s:
  • Sesma, Ignacio
  • Larraona, Gorka S.
  • Vinolas, Jordi
  • Rivas, Alejandro
  • Avila Sanchez, Sergio
Item Type: Article
Título de Revista/Publicación: Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail And Rapid Transit
Date: September 2013
ISSN: 0954-4097
Subjects:
Freetext Keywords: Train aerodynamics, train overturning, overturning risk, computational fluid dynamics, Unsteady Reynolds-averaged Navier–Stokes, bluff bodies, URANS
Faculty: E.U.I.T. Aeronáutica (UPM)
Department: Vehículos Aeroespaciales [hasta 2014]
Creative Commons Licenses: Recognition - No derivative works - Non commercial

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Abstract

In a crosswind scenario, the risk of high-speed trains overturning increases when they run on viaducts since the aerodynamic loads are higher than on the ground. In order to increase safety, vehicles are sheltered by fences that are installed on the viaduct to reduce the loads experienced by the train. Windbreaks can be designed to have different heights, and with or without eaves on the top. In this paper, a parametric study with a total of 12 fence designs was carried out using a two-dimensional model of a train standing on a viaduct. To asses the relative effectiveness of sheltering devices, tests were done in a wind tunnel with a scaled model at a Reynolds number of 1 × 105, and the train’s aerodynamic coefficients were measured. Experimental results were compared with those predicted by Unsteady Reynolds-averaged Navier-Stokes (URANS) simulations of flow, showing that a computational model is able to satisfactorily predict the trend of the aerodynamic coefficients. In a second set of tests, the Reynolds number was increased to 12 × 106 (at a free flow air velocity of 30 m/s) in order to simulate strong wind conditions. The aerodynamic coefficients showed a similar trend for both Reynolds numbers; however, their numerical value changed enough to indicate that simulations at the lower Reynolds number do not provide all required information. Furthermore, the variation of coefficients in the simulations allowed an explanation of how fences modified the flow around the vehicle to be proposed. This made it clear why increasing fence height reduced all the coefficients but adding an eave had an effect mainly on the lift force coefficient. Finally, by analysing the time signals it was possible to clarify the influence of the Reynolds number on the peak-to-peak amplitude, the time period and the Strouhal number.

More information

Item ID: 25967
DC Identifier: http://oa.upm.es/25967/
OAI Identifier: oai:oa.upm.es:25967
DOI: 10.1177/0954409713504395
Official URL: http://pif.sagepub.com/ Transit Engineers, Part F: Journal of Rail and Rapid Proceedings of the Institution of Mechanical http://pif.sagepub.com/content/early/2013/09/25/0954409713504395
Deposited by: Memoria Investigacion
Deposited on: 22 Oct 2014 15:43
Last Modified: 22 Oct 2014 15:43
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