Research On Interior Noise Prediction Of High-speed Train

With the rapid development of high-speed train in China, the traditionalmethods could not effectively control the interior noise because of the increasinginfluence of interior noise. To increase the ability of noise control and the technicalcompetitiveness of companies and enterprises, it is significant to predict the interiornoise to guide the interior acoustic design at the beginning of high-speed traindesign. This paper aims at predicting and modeling the interior noise based onstatistical energy analysis (SEA) and analysis on the main incentive of interiornoise, which could facilitate interior acoustic design, and then verify the theoreticalmodel with the help of simulation in Autosea2.On the basis of research on mechanism of vehicle/rail vertical coupling force,the vehicle/rail vertical coupling force model is built through both analyzing thestructure of vehicle and rail and properly hypothesizing, and the simulation methodof the periodic irregularity of the rail surface is proposed. By the means ofNewmark integration, the time and frequency domain of vertical coupling force iscalculated when the train runs at the speed of350km/h, and the result is contrastedwith the measured value, afterwards, the accuracy is proved.Proper turbulent model is chosen after researching on the process of fluid-solidcoupling when the train in motion, then the steady-state and transient-statecalculation model of fluctuating pressure is built based on CFX. After that, thefluctuating pressure distribution of the train surface is obtained after confirming thecrucial influence of air density change to the fluctuating pressure distribution,which provides prerequisite for the interior sound field calculation.According to the structure of high-speed train and the general SEA model, theinterior noise prediction models of the head car and middle car, two of the mosttypical models in high-speed train are built after researching on the characteristicsof train energy flow and proper hypothesis. The theoretical calculation of interiorloss factor and coupling loss factor in the coefficient matrix, then the noisedistribution in the three typical rooms, the head cab, passenger room and middle caris obtained and it plays as the guide in the acoustic design in high-speed trainrooms. The equivalent train structure is built and the noise simulation models with andwithout ornament are built through inputting relative SEA parameters, combinedwith the structural and acoustic subsystems in AutoSEA2. Then the model withoutornament is contrasted with the theoretical results, and then modification isconducted on theoretical model. The noise distribution of interior average noise andnoise in areas of1.2m in the train model with ornament, and then the noise controlmeasures of the head cab are explored in accordance with the interior acousticdesign.