A Computational Analysis of Flow Field in Twin-Track Subway Tunnel to Improve Air Quality

Abstract:

A computational model of existing Seoul subway tunnelwas analyzed in this research. The computational model was comprised of one natural ventilationshaft, two mechanical ventilationshafts, one mechanical airsupply, a twin-track tunnel, and a train. Understanding the flow pattern of the train-induced airflow in the tunnel was necessary to improve ventilation performance. The research objective wasto improve the air quality in the tunnel by investigating train-induced airflow in the twin-track subway tunnel numerically. The numerical analysis characterized the aerodynamic behavior and performance of the ventilation system by solving three-dimensional turbulent Reynolds-averaged Navier-Stokes equations. ANSYS CFX software was used for the computations. The ventilation and aerodynamic characteristics in the tunnel were investigated by analyzing the mass flowrateat the exits of the ventilation mechanicalshafts. As the train passed the mechanical ventilation shafts, the amount of discharged-air in the ventilationshafts decreased rapidly. The air at the exits of the ventilation shafts was gradually recovered with time, after the train passed the ventilation shafts. The developed mechanical air-supply for discharging dusty air and supplying clean airwas investigated.The computational results showed that the developed mechanical air-supplycould improve the air quality in the tunnel.

• Periodical: Applied Mechanics and Materials (Volume 319)
• Pages: 599-604
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.319.599
• Online since: May 2013
• Authors: Makhsuda Juraeva, Kyung Jin Ryu, Sang Hyun Jeong, Dong Joo Song
• Keywords: Indoor Air Quality, Mechanical Air-Supply, Train-Induced Flow, Twin-Track Subway Tunnel

References

[1] Jeon, J.S., Seo, J.W., Jeon, M.J., Eom, S.W., and Chae Y.Z., 2012, "Indoor Radon levels in the subway cabins of the Seoul metropolitan area", Journal of Korean Society for Atmospheric Environment, Vol.28. pp.374-383 (in korean)

DOI: 10.5572/kosae.2012.28.4.374

[2] Modic, J., 2003, "Fire simulation in road tunnels", Tunnelling and Underground Space Technology", vol. 18, pp.525-530

DOI: 10.1016/s0886-7798(03)00069-5

[3] Ogawa, T., and Fujii, K., 1997, "Numerical investigation of three-dimensional compressible flows induced by a train moving into a tunnel, Computers & Fluids, vol. 26, pp.565-585

DOI: 10.1016/s0045-7930(97)00008-x

[4] Chen, T.Y., Lee, Y.T., and Hsu, C.C., 1998, "Investigations of piston-effect and jet fan-effect in model vehicle tunnels", Journal of Wind Engineering and Industrial Aerodynamics, vol.73, pp.99-110

DOI: 10.1016/s0167-6105(97)00281-x

[5] Li, J., Peng, H., and Li S.J., 2006, "Numerical simulation of flow characteristics in bidirectional subway tunnel", Journal of Thermal Science and Technology, vol. 5, pp.331-334

[6] Waymel, F., Monnoyer, F., and William-Louis, M.J.P., 2006, "Numerical simulation of the unsteady three-dimensional flow in confined domains crossed by moving bodies", Computers & Fluids, vol.35, pp.525-543

DOI: 10.1016/j.compfluid.2004.12.006

[7] Karlsson, H. L., Nilsson, L. and L. Moller, 2005, "Subway particle are more genotoxic than street particles and induce oxidative stress in cultured human lung cells", Chem. Res. Toxicol, vol. 18, pp.19-23

DOI: 10.1021/tx049723c

[8] Song, J., Lee, H., Kim, S., and Kim, D., 2008, "How about the IAQ in subway environment and its management? " Asian Journal of Atmospheric Environment, vol.2-1, pp.60-67

DOI: 10.5572/ajae.2008.2.1.060

[9] ANSYS CFX, 2009, ANSYS Workbench, ICEM-CFD, CFX-Pre, CFX-Solver, CFX-Post User's Manual.

DOI: 10.1299/jsmeicone.2007.15._icone1510_128

[10] Kim, J.Y. and Kim K.Y., 2007, "Experimental and numerical analyses of train-induced unsteady tunnel flow in subway", Tunnelling and Underground Space Technology", vol.22, pp.166-172

DOI: 10.1016/j.tust.2006.06.001

[11] Menter, F.R, 1994, "Two-equation eddy-viscosity turbulence models for engineering applications" AIAA-Journal., vol.32, pp.269-289

DOI: 10.2514/3.12149

[12] Wilcox, D.C., 1993, "Comparison of Two Equation Turbulence Models for Boundary Layers with Pressure Gradient," AIAA Journal, vol. 31, N.9, pp.1414-1421

DOI: 10.2514/3.11790