Effect of deflector devices on the aerodynamic characteristics of high-speed maglev trains
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摘要: 由于车轨悬浮间隙的存在,高速磁浮列车的悬浮架周围流场紊乱且气动力复杂,影响列车的悬浮和导向性能。基于计算流体力学建立了3车编组的高速磁浮列车气动数值仿真模型,研究了列车气动特性及车轨间隙和悬浮架周围的流场结构,分析了3种不同形式的导流装置(板式、短楔形、长楔形)对列车气动特性的影响规律。研究结果表明:在500 km/h的运行速度下,气流通过头车鼻尖底部悬浮间隙直接冲击在头车一位端悬浮架迎风侧,形成的压差阻力使头车气动阻力大幅增大;受悬浮架扰流影响,气流在车体底部形成了大面积的正压区,直接导致头车气动升力和气动力矩大幅提高且远高于中间车及尾车气动升力。根据研究结果,改变头车鼻尖底面结构,控制进入车轨磁浮间隙的气流流量和方向,改善了列车表面压力分布情况,协同降低了列车气动阻力、气动升力和点头力矩。与原型磁浮列车相比,3种导流装置均能实现减阻降升,其中气动特性优化效果最好的长楔形导流装置可实现减小整车气动阻力3.6%、头车气动升力40.6%和头车点头力矩80.3%,综合气动性能最好。Abstract: Due to the existence of suspension gap, the flow field around the suspension frame of high-speed maglev trains is turbulent and aerodynamically complex, which in turn affects the suspension and guidance performance of the trains. Based on Computational Fluid Dynamics (CFD), a numerical simulation model of the three-car marshalling high-speed maglev train is established to study the aerodynamic characteristics and the flow field structure. The results show that the airflow through the suspension gap impacts directly on the windward side of the suspension frame of the head car at a speed of 500 km/h. This creates a differential pressure drag which increases the aerodynamic drag of the head car significantly. A large area of the positive pressure area is formed at the bottom of the car body due to the airflow turbulence of the suspension frame, leading to a large increase in the aerodynamic lift force of the head car that is much higher than that of the middle car and the tail car. According to the results, three different types of deflector devices are proposed to control the airflow through the gap by changing the structure of the nose of the head car, which can significantly improve the pressure distribution on the train surface. The aerodynamic drag, aerodynamic lift and pitch moment of the train are effectively and synergistically reduced. Compared with the original maglev train, all three types of deflector devices (plate, short wedge, long wedge) can achieve both aerodynamic drag and lift forces reduction, among which the best long wedge deflector device can reduce the overall aerodynamic drag force by 3.6%, the head car aerodynamic lift by 40.6% and the head car pitch moment by 80.3%, with the best comprehensive aerodynamic characteristics.
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表 1 列车气动力系数网格独立性检验
Table 1. Grid independence test of train aerodynamic coefficients
CD,h CD,t CL,h CL,t Mesh 1 0.123 0.087 0.366 0.165 Mesh 2 0.124 0.092 0.387 0.173 Mesh 3 0.124 0.090 0.382 0.171 表 2 导流装置外形参数
Table 2. Deflector device shape parameters
序号 形式 迎风侧倾角/(°) 背风侧倾角/(°) 长度/mm 宽度/mm 1 板式 125 125 30 1000 2 短楔形 125 5 973 1000 3 长楔形 125 2 2523 1000 表 3 设置不同导流装置列车的气动力及力矩系数
Table 3. Aerodynamic forces and moment coefficients for trains with different deflector devices
CD,h CD,m CD,t CL,h CL,m CL,t CMy,h 原型列车 0.124 0.062 0.092 0.387 0.018 0.173 −0.559 导流装置1 0.122 0.062 0.092 0.271 0.025 0.175 −0.283 导流装置2 0.122 0.064 0.089 0.270 0.023 0.169 −0.283 导流装置3 0.121 0.059 0.088 0.230 0.006 0.163 −0.110 -
[1] 宋嘉源, 李田, 张晓涵, 等. 亚声速真空管道磁浮系统气动热特性研究[J]. 空气动力学学报, 2022, 40(2): 115–121. doi: 10.7638/kqdlxxb-2021.0227SONG J Y, LI T, ZHANG X H, et al. Research on aerodynamic and thermal characteristics of subsonic evacuated tube maglev system[J]. Acta Aerodynamica Sinica, 2022, 40(2): 115–121. doi: 10.7638/kqdlxxb-2021.0227 [2] 毕海权, 雷波, 张卫华. TR磁浮列车湍流外流场数值计算[J]. 西南交通大学学报, 2005, 40(1): 5–8. doi: 10.3969/j.issn.0258-2724.2005.01.002BI H Q, LEI B, ZHANG W H. Numerical calculation for turbulent flow around TR maglev train[J]. Journal of Southwest Jiaotong University, 2005, 40(1): 5–8. doi: 10.3969/j.issn.0258-2724.2005.01.002 [3] ZHOU P, LI T, ZHAO C F, et al. Numerical study on the flow field characteristics of the new high-speed maglev train in open air[J]. Journal of Zhejiang University-SCIENCE A, 2020, 21(5): 366–381. doi: 10.3969/j.issn.0258-2724.2005.02.001 [4] 倪章松, 张军, 符澄, 等. 磁浮飞行风洞试验技术及应用需求分析[J]. 空气动力学学报, 2021, 39(5): 95–110. doi: 10.7638/kqdlxxb-2021.0206NI Z S, ZHANG J, FU C, et al. Analyses of the test techniques and applications of maglev flight tunnels[J]. Acta Aerodynamica Sinica, 2021, 39(5): 95–110. doi: 10.7638/kqdlxxb-2021.0206 [5] 胡啸, 马天昊, 王潇飞, 等.真空管道磁浮交通车体热压载荷分布特征及其非定常特性[J/OL]. [2022-11-01]. 实验流体力学.http://kns.cnki.net/kcms/detail/11.5266.V.20220913.0905.002.html.HU X, MA T H, WANG X F, et al. Distribution and unsteady characteristics of the temperature and pressure loads acting on the car-body in evacuated tube maglev transport[J/OL]. [2022-11-01]. Journal of Experiments in Fluid Mechanics.http://kns.cnki.net/kcms/detail/11.5266.V.20220913.0905.002.html. doi: 10.11729/syltlx20220084 [6] 刘堂红, 田红旗, 王承尧. 不同磁浮列车外形的气动性能比较[J]. 国防科技大学学报, 2006, 28(3): 94–98. doi: 10.3969/j.issn.1001-2486.2006.03.020LIU T H, TIAN H Q, WANG C Y. Aerodynamic performance comparison of several kind of nose shapes of maglev train[J]. Journal of National University of Defense Technology, 2006, 28(3): 94–98. doi: 10.3969/j.issn.1001-2486.2006.03.020 [7] 毕海权, 雷波, 张卫华. TR型磁浮列车气动力特性数值计算研究[J]. 铁道学报, 2004, 26(4): 51–54. doi: 10.3321/j.issn:1001-8360.2004.04.011BI H Q, LEI B, ZHANG W H. Research on numerical calculation for aerodynamic characteristics of the TR maglev train[J]. Journal of the China Railway Society, 2004, 26(4): 51–54. doi: 10.3321/j.issn:1001-8360.2004.04.011 [8] 毕海权, 雷波, 张卫华. 自然风对高速磁浮列车气动特性的影响[J]. 中国铁道科学, 2007, 28(2): 65–70. doi: 10.3321/j.issn:1001-4632.2007.02.012BI H Q, LEI B, ZHANG W H. Effects of natural wind on aerodynamic characteristics of high-speed maglev train[J]. China Railway Science, 2007, 28(2): 65–70. doi: 10.3321/j.issn:1001-4632.2007.02.012 [9] 李人宪, 刘应清, 翟婉明. 高速磁悬浮列车纵向及垂向气动力数值分析[J]. 中国铁道科学, 2004, 25(1): 8–12. doi: 10.3321/j.issn:1001-4632.2004.01.002LI R X, LIU Y Q, ZHAI W M. Numerical analysis of aerodynamic force in longitudinal and vertical direction for high-speed maglev train[J]. China Railway Science, 2004, 25(1): 8–12. doi: 10.3321/j.issn:1001-4632.2004.01.002 [10] 孟石, 周丹, 孟爽. 轨道间隙对磁浮列车气动性能的影响[J]. 中南大学学报(自然科学版), 2020, 51(12): 3537–3545.MENG S, ZHOU D, MENG S. Effect of rail gap on aerodynamic performance of maglev train[J]. Journal of Central South University(Science and Technology), 2020, 51(12): 3537–3545. [11] 丁叁叁, 姚拴宝, 陈大伟. 高速磁浮列车气动升力特性[J]. 机械工程学报, 2020, 56(8): 228–234. doi: 10.3901/JME.2020.08.228DING S S, YAO S B, CHEN D W. Aerodynamic lift force of high-speed maglev train[J]. Journal of Mechanical Engineering, 2020, 56(8): 228–234. doi: 10.3901/JME.2020.08.228 [12] 戴志远, 李田, 张卫华, 等. 气动翼对高速磁悬浮列车升力特性的影响[J]. 西南交通大学学报, 2022, 57(3): 498–505. doi: 10.3969/j.issn.0258-2724.20210855DAI Z Y, LI T, ZHANG W H, et al. Effect of aerodynamic wings on lift force characteristics of high-speed maglev train[J]. Journal of Southwest Jiaotong University, 2022, 57(3): 498–505. doi: 10.3969/j.issn.0258-2724.20210855 [13] 夏超, 单希壮, 杨志刚, 等. 风洞地面效应对高速列车空气动力学特性的影响[J]. 铁道学报, 2015, 37(4): 8–16. doi: 10.3969/j.issn.1001-8360.2015.04.002XIA C, SHAN X Z, YANG Z G, et al. Influence of ground effect in wind tunnel on aerodynamics of high speed train[J]. Journal of the China Railway Society, 2015, 37(4): 8–16. doi: 10.3969/j.issn.1001-8360.2015.04.002 [14] LI T, QIN D, ZHANG J Y. Effect of RANS turbulence model on aerodynamic behavior of trains in crosswind[J]. Chinese Journal of Mechanical Engineering, 2019, 32(5): 155–166. doi: 10.1186/s10033-019-0402-2 [15] LI T, HEMIDA H, ZHANG J Y, et al. Comparisons of shear stress transport and detached eddy simulations of the flow around trains[J]. Journal of Fluids Engineering, 2018, 140(11): 11108–1. doi: 10.1115/1.4040672 [16] LI T, DAI Z Y, YU M G, et al. Numerical investigation on the aerodynamic resistances of double-unit trains with different gap lengths[J]. Engineering Applications of Computational Fluid Mechanics, 2021, 15(1): 549–560. doi: 10.1080/19942060.2021.1895321