| Title |
A Basic Study on the Prediction of Train Noise Propagation from Korea Train Express Using a Spark Discharge Sound Source |
| Keywords |
Scale Model Experiment ; Korea Train Express ; Railway Noise ; Spark Discharge Sound Source ; Prediction |
| Abstract |
Opening the express rail which is fast, safe and convenient will bring about enormous changes to the lives of Koreans, but it is expected that its noise which is the weak point and its tremor caused by the acceleration of speed and the increase of running service might be social problems along with the noise of road traffic. For the construction of the KTX line which is pro-environmental, it is inevitable to take a measure of reducing the noise about the propagation paths of its noise, and above all, it is necessary to predict the noise at the receiving point accurately.
This paper aims at developing the sound source of the scale model experiment as a basic research to predict the rolling sound, the motor noise and the aerodynamic sound which are the main noise source of KTX. In this study, a scale model of the express rail with the scale of 1/20 was invented for the scale model experiment and a spark pulse generator with 4 channels as a noise source was made, assuming rolling noise, the motor noise and the aerodynamic noise.
The scale model experiment was done about the condition of both the noise barrier installed and the one uninstalled separately under the cases that only rolling noise is considered, that both rolling noise and motor noise are considered and that motor noise and aerodynamic noise are considered and the result of the experiment was examined by the model of calculation.
The result of the model experiment appeared to be the same with that of calculation model and at the result of model experiment, the location of noise source was apparently shown compared with the result of calculation model. And an absorptive noise barrier showed greater effect in decreasing noise than the reflexive barrier. At the result of examination about the aerodynamic noise in the case where the noise source was visible through the upper side of the noise barrier at the receiving point, the effect of sound propagation was so big that assuming the directivity of aerodynamic noise as n=0 showed a good contrast with the result of scale model experiment.
Through this study, the basis of a research that the experimental system of the scale model using spark noise source propagation can be utilized at the field of prediction of the KTX noise propagation was established. |