Low-Noise Design Of High-Speed Train Pantograph Based On Rod Section Optimization

As one main noise source of high-speed trains,when the speed increases,the aerodynamic noise of pantograph will quickly increase,exacerbating the adverse effects on passengers and the environment nearby.It is necessary to minimize the aerodynamic noise of high-speed train pantograph,and to ameliorate the noise level inside and outside the vehicle.In this paper,the aerodynamic characteristics and low-noise design of high-speed train pantographs are studied combining experiments and numerical simulation.The main work is as follows.Noise of high-speed train was systematically tested and analyzed through experiment on rail line to study the source power and distribution of noise sources outside the train under operating condition.The bogie area,pantographs,obstacle guards,and train's body-surface were judged as main noise sources outside the vehicle.The noise characteristics of pantograph area was analyzed and the result showed that the noise radiations from the knuckle-downstream direction of the pantograph was lower than noise radiations from the knuckle-upstream direction.The aerodynamic noise forecast model of pantograph was established based on large eddy simulation and Lighthill's acoustic theory to study the aerodynamic noise source characteristics,the noise generating mechanism,far-field aerodynamic noise directivit y characteristics,far-field aerodynamic noise contribution of main pantograph components,effect of choice of the knuckle-downstream or knuckle-upstream pantograph orientation and effect of train's speed.The results showed that the aerodynamic noise of pantograph was mainly composed of dipole noise caused by pulsating pressure of pantograph's rod surfaces.The aerodynamic noise had strong directionality in the symmetry plane.The panhead was the main noise source in the pantograph area.The noise radiations from the knuckle-downstrea m direction of the pantograph were lower than noise radiations from the knuckle-upstrea m direction and the difference decreased with the increasing speed.Low-noise design of high-speed train pantograph was carried on from the aspect of rod section.Optimization designs such as oval processing,hole digging and round processing are analyzed aiming at rectangular-section rod and circle-section rod.Rod sections with better aerodynamic characteristics were used to optimize high-speed train pantograph model.Noise reduction effect of low-noise design pantograph was evaluated based on the aerodynamic noise forecast model.The results showed that sound pressure level of aerodynamic noise monitoring points at the field 5 meters away from the center of pantograph in the horizonta l plane were reduced from 1.0 d B to 7.8 d B,and in the symmetry plane were reduced from 4.5 d B to 7.9 d B.In this paper,the low-noise design of pantograph was studied from the perspective of rod and the integral pantograph,providing reference for practical engineering applications.