Research On The Influence Of Truck Platoon Topology Structure On Aerodynamic Characteristics And Fuel Economy Based On The Internet Of Vehicles

With stricter emission regulations and the implementation of the "double carbon" strategy,it is important to reduce energy consumption and carbon emissions in the transportation industry to achieve carbon peaking and carbon neutrality and accelerate the construction of a strong transportation country.The development of vehicle networking and automatic driving technology provides a good operating environment for realizing vehicle formation driving.Vehicle formation driving technology can significantly reduce the energy consumption and emission of vehicle queue due to improved aerodynamic efficiency.Research shows that the degree of reduced energy consumption of queue operation is closely related to the queue configuration.Therefore,this paper takes the domestic mainstream truck as the research object,adopts the computational fluid dynamics(CFD)method,combines it with the actual wind tunnel test,explores the vehicle queue aerodynamic performance and fuel economy change the law under different topologies,and then establishes the mathematical function relationship between the vehicle queue fuel saving rate and the main configuration parameters of the queue.The specific research contents are as follows:(1)Construct a single truck virtual wind tunnel simulation experimental model and analyze its external flow field characteristics.Establish a three-dimensional model of mainstream box trucks in China through UG,compare the different models and their computational performance using Fluent software,and ultimately select the standard k-ε model as the simulation calculation model for this study.Conduct virtual wind tunnel simulation calculations on the entire vehicle,analyze the pressure field,velocity field,and airflow flow state around the vehicle,and provide a basis for subsequent multi vehicle platoon simulation calculations and comparison of aerodynamic characteristics.(2)Based on wind tunnel tests of proportionally scaled vehicle models,verify the accuracy of numerical simulation analysis.Extract 3D body size data and print the 3D vehicle model(with a ratio of 10:1).Based on the Yangzhou University wind tunnel experimental platform,conduct single-vehicle wind tunnel tests under wind speeds of 13.9m/s,15.4m/s,and 16.7m/s,and compare the test results with single-vehicle CFD simulation test data under the same wind speed conditions to ensure the accuracy of subsequent numerical simulation tests.(3)Study the changes in aerodynamic characteristics and energy savings of two and three vehicle platoons under different configuration parameters.Referring to the single-vehicle numerical simulation analysis method,establish a two-vehicle and three-vehicle virtual wind tunnel simulation analysis model,set the horizontal offset distance of the platoon(0W～1.5W),vehicle spacing(0.5L～4L),and vehicle speed(16.7m/s～25m/s),and then discuss the pressure and velocity field simulation test results of the two vehicle platoon,triangular and stepped three vehicle platoon.Explore the comprehensive effects of horizontal offset distance,vehicle spacing,and vehicle speed on the resistance coefficient of each single-vehicle in the platoon,the average resistance coefficient of the fleet,and the energy saving rate,compare and analyze the fuel economy of three vehicle fleets: straight,triangular,and stepped.The simulation test results show that due to the improvement of aerodynamic efficiency,the overall average resistance coefficient and energy saving rate of the two-vehicle and three-vehicle fleets are better than those of the single-vehicle driving state,the straight three vehicle platoon has the best fuel economy,followed by the triangular three vehicle platoon,and the stepped three vehicle platoon is the worst.(4)Establish the mathematical function between the fuel-saving rate of vehicle queues and the main configuration parameters of the fleets.According to the trend of fuel-saving rate under different configuration parameters,the mathematical relationship between the fuel-saving rate of two-vehicle queues and three-vehicle queues under different topologies concerning suitable function models is constructed to provide mathematical models for fuel-saving rate calculation of vehicle queues.Among them,the two-vehicle queue uses the exponential function model,the triangular three-vehicle and ladder three-vehicle queues use the lognormal function model.