Study On Pressure Wave Characteristics In Tunnel Of Intercity Trains

In recent years, a large number of passengers have led to serious traffic jam in most Chinese cities. To relieve people’s traveling pressure and increase the transportation efficiency, China has started to construct short distance interurban railways between cities on the basis of advanced technology of foreign high-speed railways and intercity rail transit.Many metropolises build interurban railways underground to meet the requirements of short distance between cities so that railway line can reach destination directly through the city circle. Intercity train traveling across underground tunnel at high speed will encounter the problem of pressure wave. Therefore, it is of great importance to study the pressure wave of interurban railway tunnel.This thesis introduced the features of tunnel pressure wave using five chapters.According to the requirements of intercity railway design standards released by National Railway Administration of the People’s Republic of China, the author studied a relatively matured CRH2 motor train unit at speed of 150km/h, 200km/h and 250km/h respectively as well as a single-bore double line tunnel with cross-sectional area of 602 m.One-dimensional compressible unsteady non-homentropic flow model and method of characteristics of generalized Riemann variables are adopted to study the pressure wave issue in intercity railway tunnel. Program is wrote and verified with the results of real train test, and its feasibility and correctness are proved. On the basis of this, comparisons are carried out on the pressure waves in three different tunnel structures, i.e., simple tunnel, single-shaft tunnel and tunnel with abrupt changes in the cross-sectional area. According to different operating conditions, air pressure waves in tunnel and on train are analyzed through aspects like speed,tunnel length, cross-sectional area of tunnel and station length, and their characteristics are compared in the conditions when one train passing through and when two train running in opposite directions passing through. The tunnel length on pressure wave under same speed;the speed on pressure wave under same tunnel length; different abrupt changed cross-sectional areas and station lengths on pressure wave; different air-tightness indexes on pressure wave; different train formations on air pressure wave and other conclusions are obtained through analysis and summarized at the end of every section.The conclusion it can provide reference for the building of intercity railway in aerodynamics of tunnels. It can also work as the reference data for people who study the pressure wave of the high-speed railway tunnels.