抄録
The propagation and radiation characteristics of compression wave have been studied numerically to show the effect of high and/or low-density region, which has locally different temperature or gas in tunnel near the exit on the radiated pulse. The result shows that the local high-temperature region reduces the peak values of radiated pulse by about 65 percents, due to the sound refraction through the local region Also, the present result indicates greater reduction by the local addition of different gas.
