车联网环境下乘用车节能队列研究
发布时间：2019-06-04 10:17
【摘要】：汽车工业的迅猛发展,在给人们带来生活便利的同时,也导致了交通拥堵、能源短缺、环境污染等一系列问题;科学技术的进步,使车联网成为了国际智能交通领域的新热点,引领了智能交通发展的方向,这也促使人—车—路—环境系统向信息化、智能化、环保化方向发展。相关研究表明,采用队列行驶模式不仅可以大大提高道路通行能力,减少交通事故的发生,还能减少燃油消耗和尾气排放,在提高道路交通安全水平的同时带来了节能环保效益。因此,本文采用数值模拟方法对车联网环境下乘用车节能队列进行了深入研究。本文以车联网环境为研究背景,采用队列行驶模式对乘用车进行节能研究,研究采用Driv Aer汽车模型进行空气动力特性分析,该模型不同于高度简化的Ahmed模型和SAE模型,使得试验结果更接近实际情况。选用XFlow软件进行数值模拟仿真试验,从空间离散方式、湍流模型选择和数值算法选择三个层面对该CFD仿真软件的主要特点进行了阐述,从介观动理学模型、格子玻尔兹曼方法和大涡模拟法对其基本理论基础进行了介绍。本文假设在车联网环境下进行理想的试验研究,即车间有良好的通讯且忽略车辆操作延误等因素干扰,首先研究汽车外形对队列行驶的影响,因为道路上行驶的汽车种类繁多,车身形状各不相同,所以选取三种比较有代表性的车身外形:直背式、阶背式、快背式Driv Aer汽车模型进行试验研究,所选择的三种Driv Aer模型除尾部形状结构不同外,前端几何形状完全相同。试验分别针对单车、两车队列进行仿真,通过对单车和两车队列速度场、压力场的比较分析,揭示了汽车队列行驶的减阻机理。研究结果表明,三种汽车模型队列行驶时的尾流场并不相同,但队列行驶的减阻机理是一致的:队列行驶时前车尾部的涡流与后车流场之间相互影响,后车流场的存在使前车的尾涡区域稍有减小,前车流场的“屏蔽”作用使后车头部正压区明显减小,使后车的尾涡强度降低,所以队列行驶两车的气动阻力都减小。在此研究的基础上选用阶背式Driv Aer汽车模型研究车间距对队列行驶的影响,设定仿真速度恒为22m/s,在0L~3L(L:车身长度)之间选取11种车间距,针对两车、三车队列进行数值仿真试验,并对0.5L、1L、3L三种车间距下的两车、三车队列汽车外流场速度场和压力场分别进行了分析,得到了两车、三车队列气动阻力与车间距的关系曲线和节油率与车间距的关系曲线。本文选用阶背式Driv Aer汽车模型进一步研究车速对队列行驶的影响,设定车间距为1L,采用两车队列在60km/h~120km/h之间选取了7种车速进行数值仿真试验,并对16m/s、22m/s和34m/s三种车速下的单车和两车队列的压力场进行了分析,得到了节油率随车速变化的关系曲线。本文研究为车联网环境下汽车队列行驶提供了理论依据,为以后的相关研究工作提供了方法基础。
[Abstract]:The rapid development of automobile industry not only brings convenience to people, but also leads to a series of problems, such as traffic congestion, energy shortage, environmental pollution and so on. With the progress of science and technology, the automobile networking has become a new hot spot in the field of international intelligent transportation, leading the development direction of intelligent transportation, which also promotes the development of man-car-road-environment system to the direction of information, intelligence and environmental protection. The related research shows that the queue driving mode can not only greatly improve the road capacity, reduce the occurrence of traffic accidents, but also reduce fuel consumption and exhaust emissions. At the same time, it brings energy saving and environmental protection benefits while improving the level of road traffic safety. Therefore, in this paper, the numerical simulation method is used to study the energy saving queue of passenger vehicles in the environment of vehicle networking. In this paper, based on the vehicle networking environment, the queue driving mode is used to study the energy saving of passenger vehicles, and the Driv Aer vehicle model is used to analyze the hydrodynamic characteristics of passenger cars. This model is different from the highly simplified Ahmed model and SAE model. It makes the test results closer to the actual situation. The XFlow software is used to carry out the numerical simulation experiment. The main characteristics of the CFD simulation software are described from three aspects: spatial discretization mode, turbulence model selection and numerical algorithm selection. From the mesoscopic kinetic model, The basic theoretical basis of lattice Boltzmann method and large vortex simulation method is introduced. In this paper, it is assumed that an ideal experimental study is carried out in the environment of vehicle networking, that is, the workshop has good communication and neglects the interference of vehicle operation delay and other factors. Firstly, the influence of vehicle shape on queue driving is studied, because there are many kinds of vehicles driving on the road. The shape of the body is different, so three representative body shapes are selected: straight back, step back and fast back Driv Aer vehicle models. The three Driv Aer models are selected except for the different tail shape and structure. The geometry of the front end is exactly the same. The experiments are carried out to simulate the speed field and pressure field of bicycle and two-car queue, and the drag reduction mechanism of automobile queue is revealed by comparing and analyzing the speed field and pressure field of bicycle and two-car queue. The results show that the wake flow field of the three vehicle models is not the same, but the drag reduction mechanism of the queue is the same: the vortex at the end of the front car and the flow field of the rear vehicle interact with each other when the queue is running. The existence of the rear vehicle flow field makes the wake vortex area of the front car slightly decrease, and the "shielding" effect of the front vehicle flow field obviously reduces the positive pressure area of the rear car head, and reduces the wake vortex intensity of the rear car, so the pneumatic resistance of the two vehicles in the queue is reduced. On the basis of this study, the step back Driv Aer automobile model is selected to study the influence of workshop distance on queue driving. The simulation speed is set to be 22 m / s, and 11 kinds of workshop distances are selected between 0L~3L (L: body length). For two cars, The numerical simulation experiment of the three-car queue is carried out, and the velocity field and pressure field of the external flow field of the three-car queue at the distance of 0.5L, 1L and 3L are analyzed respectively, and the two cars are obtained. The relationship curve between the pneumatic resistance of the three-car queue and the workshop distance and the relationship curve between the fuel saving rate and the workshop distance. In this paper, the back Driv Aer vehicle model is selected to further study the influence of speed on queue driving, and the workshop distance is set to 1L. Seven kinds of vehicle speeds are selected between 60km/h~120km/h by using two car lines to carry out numerical simulation experiments, and 16 m / s is used to carry out numerical simulation experiments. The pressure field of bicycle and two-car queue at three speeds of 22m/s and 34m/s is analyzed, and the relationship curve of fuel saving rate with speed is obtained. The research in this paper provides a theoretical basis for the driving of automobile queue in the environment of vehicle networking, and provides a methodological basis for the related research work in the future.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U491
[Abstract]:The rapid development of automobile industry not only brings convenience to people, but also leads to a series of problems, such as traffic congestion, energy shortage, environmental pollution and so on. With the progress of science and technology, the automobile networking has become a new hot spot in the field of international intelligent transportation, leading the development direction of intelligent transportation, which also promotes the development of man-car-road-environment system to the direction of information, intelligence and environmental protection. The related research shows that the queue driving mode can not only greatly improve the road capacity, reduce the occurrence of traffic accidents, but also reduce fuel consumption and exhaust emissions. At the same time, it brings energy saving and environmental protection benefits while improving the level of road traffic safety. Therefore, in this paper, the numerical simulation method is used to study the energy saving queue of passenger vehicles in the environment of vehicle networking. In this paper, based on the vehicle networking environment, the queue driving mode is used to study the energy saving of passenger vehicles, and the Driv Aer vehicle model is used to analyze the hydrodynamic characteristics of passenger cars. This model is different from the highly simplified Ahmed model and SAE model. It makes the test results closer to the actual situation. The XFlow software is used to carry out the numerical simulation experiment. The main characteristics of the CFD simulation software are described from three aspects: spatial discretization mode, turbulence model selection and numerical algorithm selection. From the mesoscopic kinetic model, The basic theoretical basis of lattice Boltzmann method and large vortex simulation method is introduced. In this paper, it is assumed that an ideal experimental study is carried out in the environment of vehicle networking, that is, the workshop has good communication and neglects the interference of vehicle operation delay and other factors. Firstly, the influence of vehicle shape on queue driving is studied, because there are many kinds of vehicles driving on the road. The shape of the body is different, so three representative body shapes are selected: straight back, step back and fast back Driv Aer vehicle models. The three Driv Aer models are selected except for the different tail shape and structure. The geometry of the front end is exactly the same. The experiments are carried out to simulate the speed field and pressure field of bicycle and two-car queue, and the drag reduction mechanism of automobile queue is revealed by comparing and analyzing the speed field and pressure field of bicycle and two-car queue. The results show that the wake flow field of the three vehicle models is not the same, but the drag reduction mechanism of the queue is the same: the vortex at the end of the front car and the flow field of the rear vehicle interact with each other when the queue is running. The existence of the rear vehicle flow field makes the wake vortex area of the front car slightly decrease, and the "shielding" effect of the front vehicle flow field obviously reduces the positive pressure area of the rear car head, and reduces the wake vortex intensity of the rear car, so the pneumatic resistance of the two vehicles in the queue is reduced. On the basis of this study, the step back Driv Aer automobile model is selected to study the influence of workshop distance on queue driving. The simulation speed is set to be 22 m / s, and 11 kinds of workshop distances are selected between 0L~3L (L: body length). For two cars, The numerical simulation experiment of the three-car queue is carried out, and the velocity field and pressure field of the external flow field of the three-car queue at the distance of 0.5L, 1L and 3L are analyzed respectively, and the two cars are obtained. The relationship curve between the pneumatic resistance of the three-car queue and the workshop distance and the relationship curve between the fuel saving rate and the workshop distance. In this paper, the back Driv Aer vehicle model is selected to further study the influence of speed on queue driving, and the workshop distance is set to 1L. Seven kinds of vehicle speeds are selected between 60km/h~120km/h by using two car lines to carry out numerical simulation experiments, and 16 m / s is used to carry out numerical simulation experiments. The pressure field of bicycle and two-car queue at three speeds of 22m/s and 34m/s is analyzed, and the relationship curve of fuel saving rate with speed is obtained. The research in this paper provides a theoretical basis for the driving of automobile queue in the environment of vehicle networking, and provides a methodological basis for the related research work in the future.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U491
【相似文献】
相关期刊论文 前10条
1 柳献初;平均风环境气动阻力系数[J];重型汽车;2002年02期
2 包海涛;;基于动网格技术的汽车气动阻力系数数值模拟[J];拖拉机与农用运输车;2008年06期
3 纪峻岭,赵致宽,潘可耕;气动阻力对燃料经济性的影响[J];交通科技与经济;2000年03期
4 吴志刚,魏琪,加藤征三,竹森洋平,柏康弘;导流翼片的倾角和长度在降低大后壁车辆气动阻力中的作用[J];汽车工程;2003年06期
5 吴志刚,魏琪,加藤征三,竹森洋平,柏康弘,水谷贵志,山本健太;利用多个导流装置降低大后壁车辆气动阻力的实验研究[J];实验力学;2004年02期
6 宗叶玲;康宁;;直背式轿车加速行驶气动阻力的计算[J];航空动力学报;2008年07期
7 张英朝;李杰;张U，
本文编号：2492657
本文链接：https://www.wllwen.com/kejilunwen/daoluqiaoliang/2492657.html
