Research On Aerodynamic Noise Characterization Of High-speed Train And Design For Reducing Noise

The great development of the high-speed railway in China in recent years and the increasing of the train speed lead to the railway noise problem more highlighted.aerodynamic noise has a influence on the comfort of passengers,the daily life of people along the track and the fatigue damage of related equipments.Therefore,the aerodynamic noise of the high-speed train will become the most important issues to be solved in the development of the high-speed railway.In this thesis,the aerodynamic noise of the high-speed train is studied and compared by numerical simulation and on-line measurements.Then,by using the numerical simulation method on the improvement of the pantograph are analyzed with numerical simulation study on the effect of noise reduction.This provides a solution to the noise reduction of the high-speed train aerodynamic noise.Specifically,this thesis studied the following aspects:1.Three dimensional physical models of the high-speed train and three dimensional physical models of pantograph are established.The writer takes CRH380 B high-speed train as the reference vehicle and builds the whole vehicle model with three compartments,including intermediate vehicle,the head car and the tail car.The parts with large influence on the external flow field are reserved,and the whole windshield is adopted between the carriages.The pantograph model is simplified by CX-NG pantograph,and the three-dimensional physical model of the original pantograph and the improved pantograph is established.2.Theoretical studies on aerodynamic noise of the high-speed train are targeted at.Based on the turbulence model and Light hill acoustic analogy theory,the steady and transient numerical simulation of the external flow field of the train under different running speeds(250 km/h,300 km/h,350 km/h,380 km/h),the original pantograph and the improved pantograph three-dimensional model were carried out by using the wide band noise source model and LES large eddy simulation.The noise source distribution and aerodynamic noise characteristics of the high-speed train and pantograph are analyzed.3.The far-field aerodynamic noise of the high-speed train is studied by combining the FW-H equation.According to the analysis requirements of aerodynamic noise and the far-field noise monitoring standard,the noise monitoring points are set reasonably,and the far-field noise of the train is calculated numerically.The far-field noise data are obtained and the spectral characteristics of aerodynamic noise in the far field of high-speed trains are analyzed.4.The portable data acquisition analyzer and acoustic sensor are used to measure the passing noise of CRH380 B high-speed train on the section of Beijing-Shanghai High-speed Railway Bridge,and the results are compared with the simulation results and analyzed.The noise of the high-speed train running at 300 km/h speed is tested,and the collected far-field noise data and numerical calculation results are marked,verify the feasibility of the numerical calculation method.5.The pantograph is improved and the noise reduction of pantograph is studied by numerical simulation method.Simulation results of pantograph aerodynamic noise obtained by the numerical simulation method are analyzed.The noise reduction effect of pantograph after noise reduction is evaluated reasonably and the analysis of the effect of noise reduction research and the mechanism of noise reduction is expounded,which provides scientific basis for noise reduction research.