3632 勾配を有するトンネルにおける自然換気条件下の熱気流挙動(S49-2 トンネルの空気力学と換気(2),S49 トンネルの空気力学と換気)  [in Japanese] 3632 Behavior of Thermal Plume under the condition of Natural Ventilation in a Sloping Tunnel  [in Japanese]

There are a lot of short tunnels without any ventilator in Japan, and some have a steep slope. However, although many studies of the tunnel fire in condition of ventilation were performed, they are not almost about the natural ventilation. Therefore, we examined the behavior of thermal plume in the natural ventilation tunnel with gradient by means of 3-Dimensional Large Eddy Simulation (LES). As a result, it became clear that the velocity transition in the tunnel caused by the heat growth and gradient is very large. Additionally, we confirmed that the formula for the pressure drop in case of tunnel fire derived by Asabatake, et. al. (ΔP=QU_1/(T_1AC_p)) can evaluate in the condition of backlayering.