Study On Aerodynamic Characteristics Of Overtaking Vehicles On Bridges In Crosswind Environment

Under the strong side wind environment,the safety and comfort of the vehicles on the bridge are Affected.Moreover,when the vehicle is overtaking and passing,the driving process is complicated,the two traffic fields interfere with each other,and the aerodynamic characteristics of the two vehicles are changed,so the driving safety and operation stability of the vehicle are affected,and even the traffic accidents are Induced.In this paper,the aerodynamic characteristics of non-stationary stochastic process of moving vehicle and the aerodynamic characteristics of vehicle overtaking and passing on the bridge under the condition of side wind are studied:(1)This paper briefly introduces the mechanism principle of vehicle traffic accident on wind-induced bridge,reviews the existing methods of prevention,and introduces the relative research on the aerodynamic characteristics of the bridge on the road in recent years,and illustrates the importance of the research on the unsteady aerodynamic characteristics of the mobile vehicle and the aerodynamic parameters of the vehicles on the Bridge.(2)According to the aerodynamic characteristics of the non-stationary stochastic process of mobile vehicle,the paper establishes the dynamic velocity spectrum model(transverse pulsating wind speed spectrum,longitudinal pulsating wind speed spectrum and cross Spectrum)considering the vehicle motion,and verifies the correctness of the deduced model by setting correlation parameters and comparing with the moving point theory pulsating wind spectrum deduced by Cooper.(3)The influence of the different wind deflection angle and the velocity ratio of the vehicle and wind on the fluctuating wind speed spectra of the moving vehicle is studied by means of the Von-Karman spectrum and the Simiu spectrum model,which is deduced from the various fluctuating wind speed spectrum models considering the vehicle Motion.(4)The wind tunnel test is carried out on the change of aerodynamic characteristics during the overtaking and passing of the vehicles on the bridge under the side wind environment,and the bridge model,vehicle model,test instrument and method used in the Wind tunnel Testing Institute are Introduced.(5)According to the wind tunnel test,the aerodynamic change law of two vehicle spacing and the Vehicle's overtaking and passing in the windward side and the leeward side is Studied.