2012 年 18 巻 p. 499-504
In urban flooding, cars are floated and flushed away, which may cause heavy damage on cars and buildings or lose driver’s life. In Nagasaki flood in 1982, many people died by car related accidents. It is very important to study car behaviors in flooding. Here, we studied the critical incipient condition and the subsequent floating condition experimentally, using the 1/10 and 1/18 scale car models. We also obtained the drag coefficient of partially submerged cars in the flooding flow. On the base of experimental results, we could draw the diagram of critical incipient condition of real car by flow velocity and water depth. According to the diagram, sedan typed cars are likely to be floated if the flow velocity exceeds 2m/s and the water depth exceeds 0.5m.