Study On Aerodynamic Characteristic Of Tilting Train Negotiating Curve

It's an important strategy for all the countries to develop high-speed train system at present stage. However, aerodynamic problems accompanied by the speed-up of train system are, receiving a considerable attention as practical engineering issues that should be urgently resolved. It's quite complex that the characteristic of aerodynamic and crosswind stability while titling train negotiates curve, comparing with traveling on straight level track. It is one of subjects that are not investigated yet in China. In order to improve passenger's satisfaction, titling train which negotiates curve at much higher speed tilts car body, whereas it is maybe not improved that stability of overturn and derail. So it's urgent to study on aerodynamic characteristic of it recently.The article addresses aerodynamic characteristic and crosswind stability of tilting train negotiating curve, according to the numeric simulation by CFD software for the first time, bases on theory of aerodynamic of train. Then analyses how air flow influences dynamic of vehicle system further by introducing aerodynamic results to the model of dynamic of vehicle system.It is employed the method which combining CAD and CFD technology during designing the model of numeric simulation. Firstly, model A and B which with streamline head shape together with model C with blunt head are designed by CAD technology. Secondly, the whole mesh region which contains profile of train that inputted from CAD software is created by CFD software. Then the calculation is done on environment of CFD software.The first two cars of model A and the first car of model B and C are simulated respectively. Two track formations which are level track and the track cant 5.7 degree are utilized for model A, by considering basement and rails of the track as well. The simulation are done to many cases mentioned above, by means of standard k-e turbulence model and quadratic k-e turbulence model which among the commercial CFD software star-cd that developed by FVM method, base on the theory of turbulence and numeric calculation. The visual graph results are obtained directly from CFD software, and the special parameter those users wanted are achieved by making some subroutine to exact from CFD results as well.The characteristic of flow field and aerodynamic parameter are obtained during titling train negotiating curve through numeric simulation. And it is to some extent quite similar to the results got from wind tunnel test abroad.The results show, it have not so much difference of aerodynamic characteristic between titling train negotiating curve and traveling on level track under the conditions of no crosswind. And it is also similar of stability of overturning and derailing between titling train negotiating curve and traveling on level track under the effect of not so big crosswind.The results of the paper could be served as reference foundation for that the titling train negotiates curve at much higher speed in the respects of aerodynamic firstly, and it also contributes to the research of aerodynamic and vehicle dynamic of series of trains such as high-speed train, titling train and maglev train.