Research On Aerodynamic Compensation Of Airfoil Based On The Leverage Principle For High-speed Pantograph

Today, high speed railway of modern China has become a new flag in the whole world, the mileage amount of railway owned by China has already accounted for half of the world’s high-speed rail. In terms of these aspects, China has become the world’s largest country. However, the rapid development of high-speed rail technology are inseparable with current collecting technology, and current collecting technology even determine the maximum speed of the train. Train speeds are constantly improving, The problems that how to maintain stable and reliable current collecting between pantograph and catenary continue to stand out. Especially when the train speed reach above200km/h, The influence about aerodynamic of pantograph relative to the surrounding air cannot be ignored, which will affect current collecting quality. When train run at high speed, the aerodynamic force cannot be ignored. This article consider the possibility that by using some compensation methods about improving contact pressure to control the aerodynamic force, The purpose is to control the contact force variation between pantograph and catenary, so as to improve current collecting quality to meet demands of trains at high speeds.This article theoretically analyzed pantograph aerodynamic characteristics, and summing up the current pantograph aerodynamic performance improvement measures, and concludes the means that using a movable wing installed just below the collector to generate the compensation aerodynamic force. When pantograph operate at high speed, the relative motion between the wing and air flow will produce aerodynamic forces, the article aimed at the question that how to use the air aerodynamic force to compensate the pantograph contact force, proposed two compensation schemes of the movable controlled wing based on the lever principle.About feasibility analysis of aerodynamic compensation plan based on a wing profile, there needs to establish a calculation model for analysis of the pantograph-catenary system. First, this article use mathematical methods to derive a theoretical model of catenary and pantograph system, in order to obtain theoretical basis which are useful to later calculation and analysis. Second, this paper use SolidWorks which is a three dimensional solid modeling software to build solid model of the pantograph, after defining the hinged relationship of the pantograph, then through the combined simulation interface between Matlab/SimMechanics and SolidWorks, a pantograph SimMechanics model has been completely setup. Coupling pantograph and catenary model, then analysis characteristics of the pantograph-catenary system without joining the compensation mechanism of profile. Finally, theoretical results, which is basis data about proposing the parameters of the profile and lever mechanism, has been obtain.Taking into account of the aerodynamic compensation theory about controlling the contact force variation and improving current collecting quality, which are based on an aerodynamic wing profile mechanism, no matter the attacking angle between the profile and air flow is positive and negative, there needs the profile has the same aerodynamic characteristics, so a type of symmetric airfoil-E168has been selected in this paper. After estimating the value of aerodynamic lift force, the parameters of the profile and lever mechanism has been set, including wing cross-sectional shape, projection area and leverage ratio. Two different SimMechanics models of the two type schemes about aerodynamic compensation mechanism of the wing profile based on the lever principle has been completely setup. At last, this paper carry out simulation calculations, thus compare simulation results and decide which scheme should be adopted, at the same time optimize ideas has been worken out.Finally, this article designed a simple physical model of Airfoil, including simple model wind tunnel test chamber and a symmetric E168airfoil, then an easy model wind tunnel test chamber and a physical model of airfoil has been built under laboratory conditions.