Study On Aerodynamic Characteristics Of Centre-axle Trailer Train Based On Meshless Technology

The traditional mode of transportation is difficult to adapt to the growth trend of modern logistics and transportation demand.The centre-axle trailer train provides new vitality for reducing cost and increasing efficiency of logistics transportation industry,and becomes a new mean,which has been paid attention to by commercial vehicle manufacturers,logistics transportation enterprises and traffic management departments..Aerodynamics is one of the most important characteristics of centre-axle trailer train,so it has certain significance.In this paper,the aerodynamics analysis of centre-axle trailer train composed of 3-axle van and 2-axle centre-axle trailer is carried out,and the purpose of reducing drag and increasing efficiency is realized by optimizing the structure.The studies are as follows.1)Considering the complexity of the centre-axle trailer train structure and the precision requirement of the simulation,the basic theoretical model of the simulation environment is determined.:a mesoscopic model based on particles is used to describe the macroscopic fluid motion behavior,and the lattice Boltzmann theory is used to describe the migration and collision of fluid particles.Large Eddy Simulation method based on Wall-Adapting Local Eddy viscosity model to simulate turbulence generation and dissipation;2)A 1:10 scale model is established which is consistent with the structure of the actual centre-axle trailer train,and the model retains certain structural complexity.A virtual wind tunnel model is established according to the centre-axle trailer train model size in the computational fluid dynamics software XFlow based on the Meshless technology,and the basic parameter setting of the simulation environment is determined;3)The aerodynamics analysis of van of centre-axle trailer train model is carried out,and the main factors affecting the air drag coefficient of the vehicle model are studied.The main parameter settings of the aerodynamic characteristic analysis are determined,and the air drag coefficient of the van model is obtained.The particle field,velocity field,turbulent motion and the pressure field distribution are analyzed.The aerodynamic characteristics of the van were determined.4)Through the studies of air drag coefficient,pressure field distribution,turbulence analysis,velocity field distribution,this paper analyzes the influence of the distance between the van and the centre-axle trailer on its aerodynamic characteristics,which provides the theoretical basis for the drag reduction strategy.The closed structure optimization of the spacing among the van,the centre-axle trailer and the chassis is carried out,the effect of drag reduction is analyzed,and the purpose of reducing the air resistance coefficient of the centre-axle trailer train is achieved.In this paper,the drag reduction of centre-axle trailer train is studied by means of aerodynamics method based on meshless technology,which provides an effective analysis method and drag reduction measures for energy saving and efficiency improvement of centre-axle trailer train.