The Numerical Simulation On Crossing Air Pressure Pulse By Passing Straddle-type Monorail Vehicle

As straddle-type monorail vehicle have a strong transport capacity and comprehensive benefits,it gradually become the main urban public transport.Straddle-type monorail vehicle generally run from the high ground position,the aerodynamic properties has a greater impact on the running state.Especially when passing by each other,airflow between the two vehicles has been squeezed,produced during transient pressure surges and to lead the horizontal and vertical vibration,to increase rail wear wheel.The impact pressure affect the operation of the security,performance and stability,while ride comfort inside the passenger may also have a significant impact.Based on the aerodynamics of trains and computational fluid dynamics,the author takes Chongqing Rail Line 2 straddle-type monorail vehicle as research object.For the straddle-type monorail vehicles constant intersection,no uniform intersection,the stationary intersection in windless environment three sworking conditions,and wind angle 5°?10°?30°?90°crosswind at the intersection of the flow field four sworking conditions,the flow field pressure wave and aerodynamic forces have been analysised.The airflow field of the two straddle-type monorail vehicle is numerically investigated by simulating with the software ANSYS.Specific research contents include:(1)Establish straddle-type monorail vehicle passing finite element model.Establish monorail train rigid model in CATIA,import ICEM CFD software.The surface of the already created straddle-type monorail vehicle body model and the grid for the calculating domain have been meshed to adopt partition calculation by the software ICEM CFD,and got straddle-type monorail vehicle passing finite element model.(2)Analysis the flow field pressure wave of straddle-type monorail vehicle in passing process.The study found: In the straddle-type monorail vehicle during rendezvous,process of transverse force changing with getting effect in the process of intersection in straddle-type monorail vehicle.(1).With windless environment,constant outflow rendezvous field shows symmetry,while not in constant intersection,low amplitude pressure value is less than the car speed car pressure amplitudes;As a similar analysis,windless environment is not static rendezvous conditions of constant exception.(2).At wind angle 5°?10°?30°?90°of the wind environment,pressure cloud inconstant intersection has been shown that windward side pressure wave amplitude was higher than the leeward side pressure amplitudes.and similar with straddle-type monorail vehicle rendezvous without wind.(3)When the straddle-type monorail vehicle rendezvous,aerodynamic forces was analyzed.Several of the above conditions,adopt aerodynamic forces in the body surface was analyzed with the software ANSYS.The results show: In the straddle-type monorail vehicle rendezvous process,the aerodynamic forces on the vehicle with two vehicles longitudinal relative position change.Throughout the rendezvous process,not only the size of the lateral force change,but also from time to time to change direction,led by the two vehicles mutually exclusive state into a state of mutual attraction.This would straddle-type monorail vehicle body occurs yaw,which restricts the two vehicles driving stability and security,thus affecting traffic safety.When the monorail vehicle rendezvous,The results show: When the front of the intersection,the aerodynamic lift reaches the maximum,the lateral force reaches minimum;when the front half of the intersection,the aerodynamic drag to a minimum;when the two vehicles parallel moment,the aerodynamic lift gets the minimum,the lateral force gets maximum;when the rear half of the intersection,the aerodynamic drag to a maximum.