Development of a transverse ventilation simulator for long tunnels with merging and diverging sections in urban areas

A transverse ventilation simulator has been developed for long traffic tunnels with merging and diverging sections now planned for large cities in Japan. The simulator features a built-in model for merging and diverging sections in addition to its conventional ventilation calculation model for single-tube tunnels, and it permits simulation at modified intake and exhaust rates, which may provide semi-transverse ventilation or longitudinal ventilation. This paper discusses this transverse ventilation simulator in summary and proposes guidelines for operating ventilation systems by analysis using the simulator.