Description of the flow equations around a high speed train inside a tunnel. Issue 172 (January 2018)

• Record Type: Journal Article
• Authors: Rivero, Juan Manuel; González-Martínez, Ezequiel; Rodríguez-Fernández, Manuel
• Is Part Of: Journal of wind engineering and industrial aerodynamics. Issue 172(2017)
• Page Start: 212
• Page End: 229
• Publication Date: 2018-01
• Subjects: High speed train -- Train aerodynamics -- Tunnel aerodynamics -- Order of magnitude analysis; Wind-pressure -- Periodicals; Buildings -- Aerodynamics -- Periodicals; Pression du vent -- Périodiques; Constructions -- Aérodynamique -- Périodiques; Buildings -- Aerodynamics; Wind-pressure; Periodicals
• DOI: 10.1016/j.jweia.2017.09.012
• Languages: English
• ISSNs: 0167-6105

Abstract

Abstract: The present article focuses on the analysis of the equations that describe the flow when a high speed train enters a tunnel. The disparity in time and length scales allows the problem to be decomposed in different regions and regimes when matched appropriately produce the full description of the flow. The aforementioned regions are the flow upstream and downstream of the train, the areas near the nose and tail of the train, and the flow in the gap between the train and the tunnel. The regimes are analysed based on the flow regions, time scales, length scales and velocity scales. All those regions and regimes are conveniently formulated and the flow key scales are analysed and described, which allows for a simplified and robust formulation. The aforementioned formulation is implemented in a computational program that needs some external coefficients, namely the pressure signature of the train, that should be obtained only once and it could be derived from experimental data or CFD. Comparison with experimental and numerical data from other references are provided. Finally, the thermal problem is briefly introduced and some comments on the tunnel cooling problem are considered. Highlights: Order of magnitude analysis for different regions and regimes of the flow. Coupling between the different flow regions that coexist inside the tunnel. Simplified equations when the wave structure of the flow disappears, and the analytical solution for infinitely long tunnels. A clear description of the equations for High Speed Trains in tunnels. Simplicity of the model to be used to predict the pressure, velocity and heating with time, for long tunnels.