The Experimental and Numerical Research of the Tunnel Aerodynamics

摘要

In order to further study the aerodynamics of railway train/tunnel systems, the field experiments of tunnel aerodynamics were carried out in China in May 2005. There are two main purposes in this experimental research: 1. To make the measurements of pressure waves in tunnels. The measured data are used to verify the capability of the numerical simulation program for the predicting the pressure waves in single or double track tunnels. The results showed that the maximum deviation between the measurements and the computations is less than 5%. This proved that the numerical simulation program of the tunnel pressure waves is accurate and reliable. 2. To make the measurements of the micro-pressure waves near the exit of tunnels so as to establish a database for future researches and also to gain experiences in measuring techniques of the micro pressure waves. Micro pressure waves belong to low frequency noise whose wave band is between 0～20 Hz. There are technical difficulties in measuring this kind of the low frequency noise at present. A low frequency noise sensor dedicated for this kind of measurement is developed. The uncertainty in the measurements is discussed. The measured values of the micro pressure waves are compared with the calculated values by Yamamoto formula, which relates the strength of the micro-pressure wave with the steepness of the compression wave front arriving at the tunnel exit. The results showed that the accuracy of the measured data is satisfactory.