【正文】 Gehrke et al., 2020), so the period the simulation concerns about the best period of time for simulation is from the point when at the section of ‘x = m’ (Fig. 1) and the air velocity begin to change under pistoneffect to the point when train totally stops at the station (defined as a ‘pullingin cycle’). (2) Though the pullingin cycle is a transient process, it is simplified to a steady process. (3) Because the process is presumed to a steady process, the transient velocity of test sections, which was tested in Southwest Station in pullingin cycle, is presumed to the timeaveraged velocity of test sections. 外文資料翻譯 第 5 頁 (4) The volume flow driven into the station by pullingin train is determined by such factors as BR (blocking ratio, the ratio of train crosssection area to tunnel crosssection area), the length of the train and the resistance of station etc. For existent and new stations, BRs are almost the same. Although the length of the latter train doubles that of the former which may increase the piston flow volume, the resistance of latter is greater than that of the former which may counteract this increase. So it is presumed that the piston flow volume is same for both existent and new station and that the volume flow through the passenger exits is also same. Based on this presumption, the results of the field measurements at the existent station can be used as velocity boundary conditions to predict velocity filed of new station. . Original conditions To obtain the boundary conditions for putation and simulation, such as the air velocity and temperature of enclosure, measures were done by times at Southwest Station. All data are recorded during a plete pullingin cycle. The air velocities were measured by the multichannel anemonemaster hotwire anemoscope and infrared thermometer is used to measure the temperature of the walls of the station which are taken as the constant temperature thermal conditions in the simulation. . Temperatures of enclosure Divide the platform into five segments and select some typical test positions. The distributing temperature of enclosure is shown in Table 1. It can be seen from Table 1 that all temperatures of enclosure are between 23 _C and 25 _C, there is little difference in all test positions, and the average temperature is 24 _C. So all temperatures of subway station’s walls is 24 _C in CFD putation and simulation. . Timeaveraged air velocity above the platform Fig. 1 is the location of test section and the layout of measuring points. The data 外文資料翻譯 第 6 頁 measured include 12 transient velocities in each section (A–H in Fig. 1), which were deal with section’s timeaveraged velocities in the period, 12 point’s velocities of passageway, which is used to acquire the average flow, and the velocities of each end of station, which is used to acquire the average piston flow volume. Fig. 2 is the lengthways velocities measured of platform sections, maxV is the maximum a