Abstract: In this study, an improved delayed detached eddy simulation (IDDES) method based on the shear-stress transport (SST) k-ω turbulence model has been used to investigate the underbody flow characteristics of a high-speed train operating at lower temperatures with Reynolds number Re=1.85×10⁶. The accuracy of the numerical method has been validated by wind tunnel tests. The aerodynamic drag of the train, pressure distribution on the surface of the train, the flow around the vehicle, and the wake flow are compared for four temperature values: +15 °C, 0 °C, -15 °C, and -30 °C. It was found that lower operating temperatures significantly increased the aerodynamic drag force of the train. The drag overall at low temperatures increased by 5.3% (0 °C), 11.0% (-15 °C), and 17.4% (-30 °C), respectively, relative to the drag at +15 °C. In addition, the low temperature enhances the positive and negative pressures around and on the surface of the car body, raising the peak positive and negative pressure values in areas susceptible to impingement flow and to rapid changes in flow velocity. The range of train-induced winds around the car body is significantly reduced, the distribution area of vorticity moves backwards, and the airflow velocity in the bogie cavity is significantly increased. At the same time, the temperature causes a significant velocity reduction in the wake flow. It can be seen that the temperature reduction can seriously disturb the normal operation of the train while increasing the aerodynamic drag and energy consumption, and significantly interfering with the airflow characteristics around the car body.

运行低温对高速列车气动特性的影响

[1]CEN (European Committee for Standardization), 2013. Railway Applications—Aerodynamics. Part 4: Requirements and Test Procedures for Aerodynamics on Open Track, EN 14067-4:2013. CEN.

[2]DongTY, LiangXF, KrajnovićS, et al., 2019. Effects of simplifying train bogies on surrounding flow and aerodynamic forces. Journal of Wind Engineering and Industrial Aerodynamics, 191:170-182.

[3]DongTY, MinelliG, WangJB, et al., 2020. The effect of ground clearance on the aerodynamics of a generic high-speed train. Journal of Fluids and Structures, 95:102990.

[4]DorigattiF, SterlingM, BakerCJ, et al., 2015. Crosswind effects on the stability of a model passenger train—a comparison of static and moving experiments. Journal of Wind Engineering and Industrial Aerodynamics, 138:36-51.

[5]FujiiT, KawashimaK, IikuraS, et al., 2002. Preventive measures against snow for high-speed train operation in Japan. The 11th International Conference on Cold Regions Engineering, p.448-459.

[6]GaoGJ, ZhangY, XieF, et al., 2019. Numerical study on the anti-snow performance of deflectors in the bogie region of a high-speed train using the discrete phase model. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 233(2):‍141-159.

[7]GaoGJ, ZhangY, WangJB, 2020. Numerical and experimental investigation on snow accumulation on bogies of high-speed trains. Journal of Central South University, 27:1039-1053.

[8]GhasemianM, NejatA, 2015. Aerodynamic noise prediction of a horizontal axis wind turbine using improved delayed detached eddy simulation and acoustic analogy. Energy Conversion and Management, 99:210-220.

[9]HanYD, ChenDW, LiuSQ, et al., 2020. An investigation into the effects of the Reynolds number on high-speed trains using a low temperature wind tunnel test facility. Fluid Dynamics & Materials Processing, 16(1):1-19.

[10]HuangZW, FengYH, GaoGJ, et al., 2017. Numerical research of the snow and ice accumulation on the brake calipers of the high-speed trains. Journal of Railway Science and Engineering, 14(12):2516-2524 (in Chinese).

[11]JingGQ, DingD, LiuX, 2019. High-speed railway ballast flight mechanism analysis and risk management–a literature review. Construction and Building Materials, 223:629-642.

[12]JingJE, GaoGJ, 2013. Simulation of the action effect of wind-driven rain on high-speed train. Journal of Railway Science and Engineering, 10(3):99-102 (in Chinese).

[13]KloowL, 2011. High-Speed Train Operation in Winter Climate. KTH Railway Group Publication, Stockholm, Sweden.

[14]LiuMY, WangJB, ZhuHF, et al., 2019. A numerical study of snow accumulation on the bogies of high-speed trains based on coupling improved delayed detached eddy simulation and discrete phase model. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 233(7):715-730.

[15]MenJQ, 2015. Dynamic Performance Investigation of Alpine EMU at Low Temperature Conditions. MS Thesis, Southwest Jiaotong University, Chengdu, China(in Chinese).

[16]MenterFR, 1994. Two-equation eddy-viscosity turbulence models for engineering applications. AIAA Journal, 32(8):1598-1605.

[17]NakhchiME, NaungSW, DalaL, et al., 2022. Direct numerical simulations of aerodynamic performance of wind turbine aerofoil by considering the blades active vibrations. Renewable Energy, 191:669-684.

[18]NaungSW, NakhchiME, RahmatiM, 2021. Prediction of flutter effects on transient flow structure and aeroelasticity of low-pressure turbine cascade using direct numerical simulations. Aerospace Science and Technology, 119:107151.

[19]NiuJQ, SuiY, YuQJ, et al., 2019. Numerical study on the impact of Mach number on the coupling effect of aerodynamic heating and aerodynamic pressure caused by a tube train. Journal of Wind Engineering and Industrial Aerodynamics, 190:100-111.

[20]RaghunathanRS, KimHD, SetoguchiT, 2002. Aerodynamics of high-speed railway train. Progress in Aerospace Sciences, 38(6-7):469-514.

[21]RashidiMM, HajipourA, LiT, et al., 2019. A review of recent studies on simulations for flow around high-speed trains. Journal of Applied and Computational Mechanics, 5(2):311-333.

[22]ShiJW, LiMX, ZhangSM, et al., 2021. Effect of low temperature on aerodynamic performance of pantograph. Journal of Mechanical Engineering, 57(2):190-199 (in Chinese).

[23]ShurML, SpalartPR, StreletsMK, et al., 2008. A hybrid RANS-LES approach with delayed-DES and wall-modelled LES capabilities. International Journal of Heat and Fluid Flow, 29(6):1638-1649.

[24]SuiY, NiuJQ, RiccoP, et al., 2021. Impact of vacuum degree on the aerodynamics of a high-speed train capsule running in a tube. International Journal of Heat and Fluid Flow, 88:108752.

[25]TaiBW, LiuJK, WangTF, et al., 2017. Numerical modelling of anti-frost heave measures of high-speed railway subgrade in cold regions. Cold Regions Science and Technology, 141:28-35.

[26]TengWX, 2019. Study on Dynamic Performance of High-Speed Trains at Low Temperature Environment. PhD Thesis, Southwest Jiaotong University, Chengdu, China (in Chinese).

[27]TianHQ, 2019. Review of research on high-speed railway aerodynamics in China. Transportation Safety and Environment, 1(1):1-21.

[28]WangJB, ZhangJ, ZhangY, et al., 2018a. Impact of bogie cavity shapes and operational environment on snow accumulating on the bogies of high-speed trains. Journal of Wind Engineering and Industrial Aerodynamics, 176:211-224.

[29]WangJB, GaoGJ, LiuMY, et al., 2018b. Numerical study of snow accumulation on the bogies of a high-speed train using URANS coupled with discrete phase model. Journal of Wind Engineering and Industrial Aerodynamics, 183:295-314.

[30]WangJB, MinelliG, DongTY, et al., 2019. The effect of bogie fairings on the slipstream and wake flow of a high-speed train. An IDDES study. Journal of Wind Engineering and Industrial Aerodynamics, 191:183-202.

[31]WangJB, MinelliG, DongTY, et al., 2020a. An IDDES investigation of Jacobs bogie effects on the slipstream and wake flow of a high-speed train. Journal of Wind Engineering and Industrial Aerodynamics, 202:104233.

[32]WangJB, MinelliG, ZhangY, et al., 2020b. An improved delayed detached eddy simulation study of the bogie cavity length effects on the aerodynamic performance of a high-speed train. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 234(12):2386-2401.

[33]WangJY, WangTT, YangMZ, et al., 2021. Effect of localized high temperature on the aerodynamic performance of a high-speed train passing through a tunnel. Journal of Wind Engineering and Industrial Aerodynamics, 208:104444.

[34]WangWL, LiangYW, ZhangWH, et al., 2020. Experimental research into the low-temperature characteristics of a hydraulic damper and the effect on the dynamics of the pantograph of a high-speed train running in extreme cold weather conditions. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 234(8):896-907.

[35]XieF, ZhangJ, GaoG, et al., 2017. Study of snow accumulation on a high-speed train’s bogies based on the discrete phase model. Journal of Applied Fluid Mechanics, 10(6):1729-1745.

[36]YuMG, LiuJL, DaiZY, 2021. Aerodynamic characteristics of a high-speed train exposed to heavy rain environment based on non-spherical raindrop. Journal of Wind Engineering and Industrial Aerodynamics, 211:104532.

[37]ZhangL, YangMZ, LiangXF, 2018. Experimental study on the effect of wind angles on pressure distribution of train streamlined zone and train aerodynamic forces. Journal of Wind Engineering and Industrial Aerodynamics, 174:330-343.

[38]ZhuJY, HuZW, 2017. Flow between the train underbody and trackbed around the bogie area and its impact on ballast flight. Journal of Wind Engineering and Industrial Aerodynamics, 166:20-28.