Shock Waves

, Volume 5, Issue 3, pp 127–138 | Cite as

Experimental investigation on tunnel sonic boom

  • K. Takayama
  • A. Sasoh
  • O. Onodera
  • R. Kaneko
  • Y. Matsui
Article

Abstract

Upon the entrance of a high-speed train into a relatively long train tunnel, compression waves are generated in front of the train. These compression waves subsequently coalesce into a weak shock wave so that a unpleasant sonic boom is emitted from the tunnel exit. In order to investigate the generation of the weak shock wave in train tunnels and the emission of the resulting sonic boom from the train tunnel exit and to search for methods for the reduction of these sonic booms, a 1∶300 scaled train tunnel simulator was constructed and simulation experiments were carried out using this facility.

In the train tunnel simulator, an 18 mm dia. and 200 mm long plastic piston moves along a 40 mm dia. and 25 m long test section with speed ranging from 60 to 100 m/s. The tunnel simulator was tilted 8° to the floor so that the attenuation of the piston speed was not more than 10 % of its entrance speed. Pressure measurements along the tunnel simulator and holographic interferometric optical flow visualization of weak shock waves in the tunnel simulator clearly showed that compression waves, with propagation, coalesced into a weak shock wave. Although, for reduction of the sonic boom in prototype train tunnels, the installation of a hood at the entrance of the tunnels was known to be useful for their suppression, this effect was confirmed in the present experiment and found to be effective particularly for low piston speeds. The installation of a partially perforated wall at the exit of the tunnel simulator was found to smear pressure gradients at the shock. This effect is significant for higher piston speeds. Throughout the series of train tunnel simulator experiments, the combination of both the entrance hood and the perforated wall significantly reduces shock overpressures for piston speeds ofu p ranging from 60 to 100 m/s. These experimental findings were then applied to a real train tunnel and good agreement was obtained between the tunnel simulator result and the real tunnel measurements.

Key words

Impulsive pressure wave Piston problem Perforated wall Railway tunnel Shock wave generation Sonic boom 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Aoki T, Kashimura H, Nonaka Y, Matsuo K (1992) Discharge of a compression wave from an open end of a tube. In: Takayama K (ed) Shock Waves, Proc. of the 18th Intl. Symp. on Shock Waves. Springer-Verlag, Heidelberg, pp 1331–1334Google Scholar
  2. Blake WK (1986) Mechanics of flow-induced sound and vibration, vol. 1. Academic Press, p 204Google Scholar
  3. Deckker BEL, Koyama H (1983) Motion of a weak shock wave in a porous tube. In: Archer, Milton (eds) Proc. 14th Intl. Symp. Shock Tubes Waves, Sydney pp 239–246Google Scholar
  4. Iida M (1993) Numerical studies of compression waves generated by train entering tunnels. Ph.D thesis, Univ. TokyoGoogle Scholar
  5. Kasimura H, Yasunobu T, Aoki T, Matsuo K (1994) Emission of a propagating compression wave from an open end of a tube (2nd Report, relation between incident compression wave and impulsive wave). Tran. Jpn Soc. Mech. Engineers (in Japanese) B60:71Google Scholar
  6. Lukasiewicz J (1976) Rail way game. Carlton ContemporaryGoogle Scholar
  7. Matsuo K, Aoki T (1992) Wave problems in high-speed railway tunnels. In: Takayama K (ed) Shock Waves, Proc. of the 18th. Intl. Symp. on Shock Waves. Springer-Verlag, Heidelberg, pp 95–102Google Scholar
  8. Onodera H, Takayama K (1990) Shock wave reflection over wedges with suction. Tran. Jpn Soc. Mech. Engineers (in Japanese) B56:112Google Scholar
  9. Onodera H, Takayama K (1992) An analysis of shock wave propagation over perforated wall and its discharge coefficient. Tran. Jpn Soc. Mech. Engineers (in Japanese) B58:1408Google Scholar
  10. Ozawa S, Moritoh Y, Maeda T, Kinoishita M (1976) Investigation of pressure wave radiated from a tunnel exit (in Japanese). Railway Tech Res Rep, The Railway Tech Res Inst, Japan Nat Railways 1023Google Scholar
  11. Ozawa S (1979) Studies of micro-pressure wave radiated from a tunnel exit. Railway Tech Res Rep, The Railway Tech Res Inst, Japan Nat Railways 1121Google Scholar
  12. Rudinger G (1957) The reflection of pressure waves of finite amplitude from an open end of a duct. J. Fluid Mech. 3:48Google Scholar
  13. Sajben M (1971) Fluid Mechanics of train-tunnel systems in unsteady motion. AIAA J 9:1538–1545Google Scholar
  14. Sasoh A, Onodera O, Takayama K, Kaneko R, Matsui H (1994a) Experimental study of shock wave generation by high speed train entrance in to a tunnel (in Japanese). Trans Jpn Soc Mech Engineers, in pressGoogle Scholar
  15. Sasoh A, Onodera O, Takayama K (1994b) Scaled train-tunnel simulator for weak shock wave generation experiment. Rev. Sci. Instrum. 65:3000Google Scholar
  16. Sasoh A, Funabashi S, Saito T, Takayama K (1994c) A numerical and experimental study of sonic boom generated from high speed train tunnels. In: Proc of the 19th Int Symp on Shock Waves. Springer-Verlag, Heidelberg, in pressGoogle Scholar
  17. Sasoh A, Onodera O, Takayama K, Kaneko R, Matsui H (1994d) Experimental investigation of the reduction of railway tunnel sonic boom (in Japanese). Trans Jpn Soc Mech Engineers, submittedGoogle Scholar
  18. Shapiro AH (1983) The Dynamics and Thermodynamics of Compressible Fluid Flow, vol. 2. Robert E Krieger Publ, Reprint EditionGoogle Scholar
  19. Stollery JL, Phan KC, Garry KP (1981) Simulation of blast waves by hydraulic analogy. In: Treanor CE, Hall JG (eds) Shock Tubes and Waves, Proc. 13th Intl. Symp., pp 781–786Google Scholar
  20. Szumowski AP (1971) Attenuation of a shock wave along a perforated tube. In: Stollery JL, Gaydon AG, Wen PR (eds) Shock Tube Research, Proc. 8th Int. Symp. Shock Tubes. Chapman & Hall 14Google Scholar
  21. Takayama K, Saito T, Sasoh A, Onodera O, Funabashi S, Kaneko R, Matsui Y (1993) A numerical and experimental study of sonic boom generated from high speed train tunnels. Int Conf on Speedup Technology for Railway and Maglev Vehicles, Nov. Yokohama pp 305–310Google Scholar
  22. Wu JHT, Ostrowski PP (1971) Shock attenuation in a perforated duct. In: Stollery JL, Gaydon AG, Wen PR (eds) Shock Tube Research, Proc. 8th Int. Symp. on Shock Tubes. Chapman & Hall 15Google Scholar

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • K. Takayama
    • 1
  • A. Sasoh
    • 1
  • O. Onodera
    • 1
  • R. Kaneko
    • 2
  • Y. Matsui
    • 2
  1. 1.Shock Wave Research Center, Institute of Fluid ScienceTohoku UniversitySendaiJapan
  2. 2.East Japan Railway Co.TokyoJapan

Personalised recommendations