448 トンネル火災時の自然換気口の排熱効率(S40-2 火災科学とその応用(2),S40 火災科学とその応用)  [in Japanese] 448 Exhaust Heat Efficiency of Natural Ventilation Portal on the Tunnel Fire Accident  [in Japanese]

The quantity of exhaust heat flow from a natural ventilation opening installed at the tunnel ceiling is examined by fire experiments by the model tunnel. As a result, It is clarified that the exhaust heat flow is depe nded on the thermal fume temperature just before the ventilation opening, and the non-dimensional exhaust heat flow is proportional to the 5/3th power of ratio of non-dimensional thermal flow and Froude number. It is confirmed that the simulation result by LES is corresponding to experiment result well. The exhaust heat flow is influenced by the aspect ratio of exhaust opening and the exhaust performance of the shape extend ed in the direction of width is high er.