Aerodynamic Coefficients of a High-Speed Train in Presence of Windbreaks With Different Gap Configurations

2020 ◽  
Author(s):  
Elia Brambilla ◽  
Gisella Tomasini ◽  
Stefano Giappino
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Full Scale ◽  
High Speed Train ◽  
European Standard ◽  
Aerodynamic Coefficients ◽  
Scaled Model ◽  
Wind Tunnel Tests ◽  
Cfd Analyses ◽  
High Band

Abstract In the present paper the force aerodynamic coefficients measured, according the European Standard Specifications, by means of wind tunnel tests carried out on a 1:15 scaled model of ETR1000 train in presence of different windbreaks configurations, are presented. In particular, 3m high band barriers (40% of porosity) have been tested with different gaps (from 0,5m to 30m, full scale) in the windbreaks and considering different positions of the train with respect to the gaps. The results shown in this paper allow to evaluate the effect of different windbreak parameters (gap amplitude, train position) on the train overturning risk and they represent a complete database for validation of CFD analyses.

Open Rotor Design Strategy: From Wind Tunnel Tests to Full Scale Multi-Disciplinary Design

2015 ◽  
Author(s):  
Jonathan Vlastuin ◽  
Clément Dejeu ◽  
Anthony Louet ◽  
Jérôme Talbotec ◽  
Ingrid Lepot ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Design Methodology ◽  
Wind Tunnel Test ◽  
Design Strategy ◽  
Design Guidelines ◽  
Full Scale ◽  
Wind Tunnel Tests ◽  
Open Rotor ◽  
Definition Of

For several years, Safran has been involved in the design and optimization of contra rotating open rotors. This innovative architecture is known for allowing drastic reduction in fuel burn, but its development is facing complex technological challenges such as acoustics, aerodynamics, and weight penalty due to the mechanical complexity of an Open Rotor. Since 2010, Safran has been developing the experimental test bench HERA (1/5 mock-up scale) to improve the understanding of the complex aerodynamics and acoustics phenomena involved in the counter rotating propellers configuration. Isolated and installed low speed and high speed wind tunnel campaigns, including PIV measurements have been extremely helpful in defining design guidelines for full scale open rotor specification. These tests have been used as CFD feed-back among other purposes. An iterative process involving CFD optimization (in close collaboration with Cenaero) and wind tunnel test campaigns has been developed over the last 4 years and has led to the definition of an innovative design strategy, which has been successfully tested during the process of the full scale counter rotating propellers design for the SAGE2 ground test demonstrator engine. This phase has evidenced the absolute necessity of a multi-disciplinary design method when it comes to full scale and “rig-ready” design. Ensuring high propulsive efficiency and at the same time, minimizing the acoustic level, while maintaining severe mechanical constraints such as weight, inertia and proper dynamic positioning under control, requires a dedicated and integrated “all inclusive” design process. The aim of this paper is to present the design methodology and some of the wind tunnel tests results carried out over the last 4 years, which have led to the definition of a novel multidisciplinary design methodology that involves CFD, FEM and acoustics.

scholarly journals Anechoic wind tunnel tests on high-speed train bogie aerodynamic noise

2016 ◽  
Vol 5 (2) ◽  
pp. 87-109 ◽  
Author(s):  
Eduardo Latorre Iglesias ◽  
David J. Thompson ◽  
Malcolm Smith ◽  
Toshiki Kitagawa ◽  
Nobuhiro Yamazaki
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Aerodynamic Noise ◽  
High Speed Train ◽  
Wind Tunnel Tests

Analysis of High Speed Train Flow Structures Under Crosswind

2015 ◽  
Author(s):  
Terence Avadiar ◽  
James Bell ◽  
David Burton ◽  
Heman Cormaty ◽  
Chao Li
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
High Speed ◽  
Streamwise Vortex ◽  
Full Scale ◽  
Full Length ◽  
Flow Structures ◽  
High Speed Train ◽  
Velocity Measurements ◽  
Through Flow

The flow structures along the length of a High-Speed Train (HST) under crosswind are investigated in a wind tunnel, through flow visualisations and velocity measurements at various angles of yaw. Surface visualisations show the development of a streamwise vortex originating at the nose that travels longitudinally along the length of the train. In addition, the hypothesis that flow structures repeat when the boundary layer (BL) on the roof of the HST model is pushed off is tested, with a view to analysing the effectiveness of using shortened HST models to accurately represent full-length trains in a wind tunnel. It would appear that using a shortened train model cannot completely model full-scale HSTs at realistic yaw angles using this theory.

scholarly journals Structure Clearance Design in Wind Tunnel Tests with Implications for Aerodynamic Drag of High-Speed Trains

2021 ◽  
Author(s):  
Zhixiang Huang ◽  
Hanjie Huang ◽  
Weiping Zeng ◽  
Li Chen ◽  
Renyu Zhu
Keyword(s):  
Reynolds Number ◽  
Wind Tunnel ◽  
Drag Coefficient ◽  
Distribution Pattern ◽  
High Speed ◽  
Aerodynamic Drag ◽  
High Speed Train ◽  
Wind Tunnel Tests ◽  
High Speed Trains

Abstract The influences of vestibule diaphragm gap, wheel-rail clearance, and strut-plate gap on the aerodynamic drag of a 1/8th-scale high-speed train model were investigated in an 8 m×6 m wind tunnel. The Reynolds number was set to 2.2×106 based on train height. It was found that the variation of the vestibule diaphragm gap changed the aerodynamic drag distribution pattern of each car; the drag coefficient of the head and middle cars might change as high as 45%; however, the change in the drag coefficient of the total train was very small. The effects of the strut-plate gap on the aerodynamic drag of each car and the total train were small. The effect of the wheel-rail clearance on the drag of the head car was not significant. It was suggested that the vestibule diaphragm gap, strut-plate gap and wheel-rail clearance of the 1:8 scale high-speed train model should not be greater than 11, 10, and 9 mm, respectively.

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