JR-East has been working on a research and development project to increase Shinkansen operation speed to 360 km/h. Methods of wayside noise reduction arise as major issues when increasing the Shinkansen's operating speed, as it is necessary to keep wayside noise levels within those of existing Shinkansen trains, even at a speed of 360 km/h. Two high-speed test trains were developed: "FASTECH360S" (running only on Shinkansen lines) and "FASTECH360Z" (running on both Shinkansen and conventional lines converted to Shinkansen gauge). Both of the trains feature several new types of equipment for reducing pantograph noise and noise from the lower part of cars, which have the greatest impact on overall noise level in series E2-1000, operating at a maximum speed of 275 km/h. Running tests were conducted with the FASTECH360 trains to measure wayside noise at a point 25 meters from the center of the track and 1.2 meters above the ground. The results show that to operate at the same noise levels as trains in service (series E2 and E3 (coupled) running at 275 km/h), FASTECH360S and FASTECH360Z (coupled) would have to run at approximately 330 km/h, and FASTECH360S (solo) at approximately 340 km/h. Although the goal of 360 km/h is yet to be attained, it was confirmed that the countermeasures incorporated in the FASTECH360 trains greatly reduced wayside noise. These measures are used for the new generation Shinkansen trains, "Series E5" which have been in operation on the Tohoku Shinkansen line since March 2011.

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Noise generated from Shinkansen trains mainly consists of wheel/rail noise, bridge noise and aerodynamic noise. Generally rolling noise and structure-borne noise from a viaduct increase in proportional to the second to third power of the train speed, whereas the aerodynamic noise increases in proportional to the sixth power of the train speed. Past studies showed that the aerodynamic noise becomes dominant at above 300km/h, and the main sources of the aerodynamic noise are the pantographs and bogies. In particular, aerodynamic bogie noise is important even if noise barriers are installed since the number of bogies are much larger than pantographs. This study focuses on the aerodynamic bogie noise for high-speed trains. A new measurement method is proposed to identify the source of the aerodynamic bogie noise precisely in wind tunnel test by using a porous plate. A part of the ground under a bogie is replaced by a porous plate which lets the sound wave propagates pass through while blocking off the air flow. This measurement method makes it possible to determine the sound source of the bogie in detail. It is found that traction motors and gear unit, which are located downstream in the bogie section, are dominant sound sources. Based on this knowledge, two mitigation measures for aerodynamic bogie noise are proposed. It is found that both of them reduce the aerodynamic bogie noise about 5dB in the frequency range of 250 to 315Hz.

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A method has been developed for predicting the aerodynamic noise from the bogie of a high-speed train using a two-dimensional microphone array in a low-noise wind tunnel. First, the mean velocity distribution of flow was simulated precisely in the low-noise wind tunnel. Next, aerodynamic noise generated by the bogie, hereinafter referred to as aerodynamic bogie noise, was estimated from the noise source distribution measured with the two-dimensional microphone array. Finally, based on the experimental results, the predicted noise generated from the lower part of the car (i.e. the total of the aerodynamic noise estimated through the proposed method and the rolling and machinery noise estimated in a previous study) was compared with the measurement data obtained near the track in the field test. It was found that the predicted sound pressure level showed good agreement with those measured in the field test. This suggests that the proposed method is appropriate to estimate the aerodynamic bogie noise quantitatively. It was also shown that the contribution of the aerodynamic bogie noise to the total noise generated from the lower part of the car is greater than that of rolling and machinery noise, especially below 500 Hz.

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In order to calculate aerodynamic noise radiated from a complex-shaped body such as a pantograph of Shinkansen, an algorithm of the boundary element method for solving shape-adapted Green's functions is parallelized. The dense matrix of pluralistic simultaneous linear equations is divided and reallocated artfully on local memories assigned to each CPU of a massively parallel computer, which enable to handle numerical models with a large number of boundary elements. After modification, bench mark tests demonstrate high parallel performance with hundreds of processes. Then incompressible flow around the pantograph is calculated by the large eddy simulation (LES), and its results are coupled with shape-adapted Green's functions to evaluate aerodynamic noise based on formulas of vortex sound theory. By extracting the net contribution from diffracted and scatted sound sources that are distributed downstream of shafts and covers, sound pressure in the far field proves to agree well with wind tunnel experimental data.

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This presentation explains the present state and the advantages of the Tokaido Shinkansen, which pioneered high speed railways in the world, and gives a brief survey of the Superconducting Maglev, a next generation high speed railway.

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Traffic demands increased in urban area and intercity after economical growth in BRICS and other countries under development. It raises rapidly road transport which conducts CO2 emissions and inconvenience of space utility planning in these countries. Then Mass Rapid Transit Systems and HSR are required to solve the problems and being planned. Japanese Railway Industry has an opportunity to join these projects. However a lack of internationally recognized standards and certification system makes obstacles for Japanese Railway Industry entering into the international market by using JIS or Japanese standards. It is urgently required to settle standards and certification system which can demonstrate superiorities of Japanese Railway Technologies. RAMS will be available tool to enforce the issue.

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