The use of non-smooth surfaces to control the wake of a high speed train

Abstract

To solve some problems caused by the wake of a high-speed train, the control process, especially the mechanism of the non-smooth surface for controlling the wake of a high-speed train, is studied by using the detached eddy simulation. The numerical simulation method is validated by using the data from a wind tunnel experiment reported in literature. To study the passive control of the wake, the non-smooth surface is arranged on the front surface and the side surface of the train, respectively. The changes of the vortex structure, velocity, and aerodynamic drag before and after the control are presented, and then the flow control mechanism of the non-smooth surface is explored in detail. The results show that by arranging the non-smooth surface on the front and side surface of the tail car, the vortex motion in the tail of the train can be slowed down and the influence region of the wake can be shortened. At the same time, the velocity fluctuation amplitude in the wake region of the train apparently decreases and the aerodynamic drag of the train decreases after the control.

Keywords

High-speed train wake non-smooth surface vortex aerodynamic drag

Get full access to this article

View all access options for this article.

References

Baker

. The flow around high speed trains. J Wind Eng Ind Aerodyn 2010; 98: 277–298.

Bell

Burton

Thompson

, et al. Moving model analysis of the slipstream and wake of a high-speed train. J Wind Eng Ind Aerodyn 2015; 136: 127–137.

Hemida

Baker

Gao

. The calculation of train slipstreams using large-eddy simulation. Proc IMechE, Part F: J Rail and Rapid Transit 2014; 228: 25–36.

Bell

Burton

Thompson

, et al. Dynamics of trailing vortices in the wake of a generic high-speed train. J Fluids Struct 2016; 65: 238–256.

Bell

Burton

Thompson

, et al. Flow topology and unsteady features of the wake of a generic high-speed train. J Fluids Struct 2016; 61: 168–183.

Bell

Burton

Thompson

, et al. The effect of tail geometry on the slipstream and unsteady wake structure of high-speed trains. Exp Therm Fluid Sci 2017; 83: 215–230.

Schulte-Werning

Heine

Matschke

. Slipstream development and wake flow characteristics of modern high-speed trains. ZAMM 2001; 81: 789–790.

Muld

Efraimsson

Henningson

. Flow structures around a high-speed train extracted using proper orthogonal decomposition and dynamic mode decomposition. Comput Fluids 2012; 57: 87–97.

Pope CW. Effective management of risk from slipstream effects at trackside and platforms. Rail Safety and Standards Board–T425 report, 2007.

10.

Krajnović

Fernandes

. Numerical simulation of the flow around a simplified vehicle model with active flow control. Int J Heat Fluid Flow 2011; 32: 192–200.

11.

Han

Krajnović

Basara

. Study of active flow control for a simplified vehicle model using the PANS method. Int J Heat Fluid Flow 2011; 42: 139–150.

12.

Yao

Sun

Guo

, et al. Numerical study on wake characteristics of high-speed trains. Acta Mech Sin 2013; 29: 811–822.

13.

Mellet

Létourneaux

Poisson

, et al. High speed train noise emission: Latest investigation of the aerodynamic/rolling noise contribution. J Sound Vib 2006; 293: 535–546.

14.

Liu

. Study on the influence of the nose slenderness ratio of high-speed train on the aerodynamic noise. Chin J Theor Appl Mech 2017; 49: 985–996.

15.

Bixler

Bhushan

. Shark skin inspired low-drag microstructured surfaces in closed channel flow. J Colloid Interface Sci 2013; 393: 384–396.

16.

Wang

Tan

, et al. Reduction in the aerodynamic drag around a generic vehicle by using a non-smooth surface. Proc IMechE, Part D: J Automobile Engineering 2017; 231: 130–144.

17.

Brackston

Wynn

Morrison

. Modelling and feedback control of vortex shedding for drag reduction of a turbulent bluff body wake. Int J Heat Fluid Flow 2018; 71: 127–136.

18.

Minelli

Hartono

Chernoray

. Aerodynamic flow control for a generic truck cabin using synthetic jets. J Wind Eng Ind Aerodyn 2017; 168: 81–90.

19.

Choi

Jeon

Choi

. Mechanism of drag reduction by dimples on a sphere. Phys Fluids 2006; 18: 041702.

20.

Xia

Wang

Shan

, et al. Effects of ground configurations on the slipstream and near wake of a high-speed train. J Wind Eng Ind Aerodyn 2017; 168: 177–189.

21.

Hunt JCR, Wray AA and Moin P. Eddies, streams, and convergence zones in turbulent flows. In: Proceedings of the summer program, Center for Turbulence Research, 1988, pp.193–208.

22.

Xia

Wang

Bao

, et al. Unsteady flow structures in the wake of a high-speed train. Exp Therm Fluid Sci 2018; 98: 381–396.