Study On The Noise Mechanism And Control Technology Of High-Speed Train Bogie Area

Noise performance is the core index of high-speed trains and a key factor in high-speed rail technology competition around the world.As the main sound source of high-speed trains,noise in bogie area is of great significance to study its production mechanism and control countermeasures.It is also a key problem facing the implementation of the "going global" strategy of Chinese high-speed railway and the development of high-speed trains with independent intellectual property rights.This essay fixates at the significant difficulties in regional noise of high-speed train bogie area,deriving from three aspects: sound source mechanism,transmission path and vehicle noise,thus forwarding reasonable and effective control measures.The research includes research of regional noise characteristics in bogie area based on extensive route tests,wheel rail noise and pneumatic noise mechanism,and bottom-up systematic control countermeasures in bogie area.The research results of this essay can provide a reasonable project for the comprehensive and effective noise reduction of "source-path" in the high-speed train bogie area,which has significant engineering application value and referential significance for scientific research.To begin with,this essay summarizes the research status in wheel-rail noise,pneumatic noise,interior noise and other related control measures of high-speed train.Then summarizes the main existing problems in bogie regional noise research.Furthermore,carries out specific research work among the following three parts:(1)Study on noise characteristics of bogie area based on experimental measurementFirst,carry out the tests of bogie area and interior noise characteristics of different operation speed,route section and operation mileage.Then,analyze the variation laws of total noise level,spectrum characteristics,distribution characteristics and key factors throughout the railway carriage in the bogie area.Furthermore,aimed at the source quantification of interior noise of high-speed trains,based on inferior noise source recognition and transmission path analysis method in different working conditions,establish the "sound-source-response" transmission path analysis model.Moreover,study the contribution of interior trim panels,as well as air excitation and structural excitation to the noise in different regions and mechanical loads.As a result,the vibration of the area above and below the train is the main contributing orientation of the passenger room noise,and the structural excitation contribution to the interior noise is greater than the air excitation.(2)Study on the noise mechanism of the bogie region based on numerical simulationUse numerical simulation and experimental verification method,the noise generation mechanism is carried out in the bogie area.Integrate interior noise prediction analytical model.Analyze the transmission mechanisms of the noise around the bogies in the aspects of wheelrail noise and aerodynamic noise.First,consider high-speed train wheelset flexibility,high-speed rotation,gyroscopic effect,high-speed moving Doppler effect and high-frequency excitation.Specifically,consider track structure infinity,periodicity,high-speed and other vital influential factors.Create a high-speed wheel-rail model of high-frequency vibration and acoustic radiation predication and analysis.Analyze the vibration and acoustic radiation characteristics of high-speed wheel and rail running on ballastless tracks of high-speed railway.Study the influence of noise field distribution,skirt structure and noise reduction measures on high-speed wheel-rail noise characteristics.It is shown that at the medium frequency range of 500～2500 Hz,wheel-rail noise is dominated by orbital noise.While below 400 Hz and above 3150 Hz,wheel-rail noise is dominated by wheelset noise.Second,with the help of the "pneumatic-acoustic" air tunnel test platform,the air tunnel test is designed for the evaluation of pneumatic noise characteristics and pneumatic noise inhibition effect of high-speed train model with 1:3 head train noise reduction ratio and noise reduction measures.The combination of surface microphone,far-field free-field microphone and microphone arrays are used to analyze the regional noise characteristics and key factors.Then,in order to clarify the pneumatic noise mechanism of the bogie area,establish the pneumatic noise prediction and analysis model.Calculate the pulsation pressure on the geometric surface of the train body and the vortex stripping structure.Then reveal the pneumatic noise reduction mechanism at the bottom of the barrier collector.Finally,based on the statistical energy analysis method and power flow equation,establish the high-speed train noise and transmission path analysis model,using experimental measurement for the model verification.Carry on the interior noise transmission path analysis and the sensitivity analysis of key influencing factors.Then study the interior noise transmission mechanism in the bogie area.(3)Research on the key technology of noise control in the bogie areaBased on the analysis results of the key influencing factors of high-speed wheelset noise,fixating on four typical damping wheels,vibration acoustic radiation characteristic experiments were carried on in the acoustic laboratory.And the damping properties and noise reduction effects of the four damping wheels were analyzed.The effect of the damping wheel and track parameters on the high-speed wheel rail noise were calculated and analyzedBased on the "pneumatic-acoustic" wind tunnel test,the aerodynamic noise suppression mechanism and its noise reduction effect of different pneumatic noise reduction combination measures were studied.The results indicated that the pneumatic noise combination control measures can superposition the noise reduction ability of different measures in a specific frequency band,and then reduce the aerodynamic noise in the full frequency band.Based on the acoustic laboratory test,the acoustic insulation performance of several typical floor and side wall structure plans were studied,and the optimized configuration scheme based on "sound insulation-sound absorption-sound insulation" mode was proposed.At last,through the noise separation method and the interior noise sensitivity analysis,the abovementioned noise reduction effect of the vital control technology in the bogie area was comprehensively evaluated...