Research On The Dynamic Performances Of Multi-Rigid Body System Of High-Speed Train Based On Aerodynamic Loads

With the development of science and technology,the operation capability of High-speed train becomes stronger,and it has faster speed,so we have to confront and solve those problems which was ignored at low speeds while becoming more and more acute with the increase of operating speeds.Among them,the aerodynamics of high-speed train is the most tough,which directly affects the dynamic performance of whole train system,even impact the safety,stability and comfort of the train.Therefore,it is worth researching on the aerodynamic problems of high-speed train,and understanding and grasping the flow field structure and aerodynamic characteristics around trains under different driving conditions,and then researching on the influence of dynamic performance under pneumatic loading.In this article,we select a type of CRH as the research object to study the effect of dynamic behavior under aerodynamic load by the utilize of fluid dynamic simulation and multi-body dynamic simulation.I mainly did the following work:1.The three car marshalling 1:1 CRH geometrical model(without considering bogie,pantograph and other small parts)has been built by three-dimensional modeling software CATIA,making use of fluid numeric simulation software STAR-CCM+,I studied on the transient aerodynamic characteristics under high-speed train sustainable acceleration running condition in the absence of under the action of cross wind,and steady aerodynamic characteristics of a train driving at high speeds under the action of different cross-wind speed respectively.I also analyzed the law of aerodynamic force changing with train speed and cross-wind speed,showed the flow field structure around the train and body surface pressure distribution characteristics,introduced the involution and development of vortex,and have recorded aerodynamic force data under each working condition.2.The same three-car marshalling CRH multi-rigid body dynamic model has been established in multi-body dynamic software SIMPACK,and aerodynamic load loading plan has been made respectively for having cross-wind or not.Co-simulation of MATLAB and SIMPACK has been used for the absence of cross-wind conditions,for wind-cross conditions,assembly function has been used to realize the one-way coupling from the train aerodynamics to multi-body dynamics.3.On the basis of the above work,contrast studies about the train dynamic characteristics considering or without considering the transient aerodynamic drag in the sustainable acceleration process in the absence of under the action of cross-wind have been made,the time domain graph and frequency domain graph of important components response results have been given,also,I analyzed the train dynamic behavior,and pointed out the influence of loading aerodynamic drag.I researched the train safety under cross-wind conditions,the results show that derailment coefficient and rate of wheel load reduction maximum value increase as the train speed and cross-wind speed increase,particularly the head-car,and head-car safety is the biggest concern under the action of cross-wind.Finally,method for determining the maximum permissible speed has been given about trains running on the cross-wind environment.This study provides an important reference for the coupling of aerodynamics and multi-body dynamics of high-speed trains,which is of great significance for the development of train speed-up schemes,the planning of operation lines,the determining of highest safe speed of train operations and the maximum safe cross wind speed.