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Indexed by:会议论文

Date of Publication:2013-09-18

Included Journals:EI、Scopus

Page Number:27-37

Abstract:In this work, a numerical study is developed to analyze effects of vehicle speed and spacing on the ventilation in a highway curved tunnel with a radius of 600 m. The air speed in the tunnel and the effective piston effect coefficient are taken to demonstrate the contribution of the piston effect to the ventilation. The air speed near outlet rises as the vehicle approaches, whereas the air speed near inlet decreases gradually after the vehicle departs. Whilst the vehicle is moving through the measured section, the air speed variation is seen to rise and fall in a saw like form. The wake effect of the vehicle is considered to be responsible for the unreasonable effective piston effect coefficient near outlet. A fully developed airflow near inlet in the tunnel gives us an intelligible result. The air speed increases significantly as the vehicle speed and vehicle spacing in the tunnel increase. Decreasing vehicle spacing and increasing vehicle speed cause the vehicle downstream to travel in the high-speed wake. There is a resultant drop in airflow volume. Consequently, the effective piston effect coefficient increases with the increase of vehicle spacing and the decrease of vehicle speed. The effective piston effect coefficient is concluded among 0.7 to 0.85 in this study. ? BHR Group 2013.