Experimental study on fire propagation and temperature distribution of passenger car under different opening conditions

In order to investigate the effect of opening size on the fire of passenger car compartment in the tunnel, a 1:2 reduced-scale model of passenger car compartment constructed by galvanized steel was established. Six fire experiments were carried out through changing the opening size of the model. The weightings of the compartment opening area and the height were calculated. The law of conservation of mass and energy was used to calculate the heat release rate, and the temperature field inside the car compartment was also analyzed. The major conclusions are summarized as follows: With the increase of the opening factor, the burning time is gradually reduced and the heat release rate of the fire increases first and then decreases. The transmission speed of temperature in the horizontal direction increases first and then decreases, while in the vertical direction it decreases initially, followed by an increase, but then decreases again. The temperature transmission speed in the horizontal direction is much larger than it in the vertical direction. All these results are significantly important for fire safety design of passenger cars and evaluating fire hazard of passenger car fire.