Study of the flame flow and combustion characteristics of pool fires around a bluff body in the ship engine room

In the development of a fire, all kinds of equipment in ship cabins cause flames to flow around them, which greatly affects the combustion characteristics of the flames. Experimental studies were conducted on a pool of 80 cm x 6 cm x 5 cm containing a bluff body with a diameter of 2 cm and a height of 15 cm. Using diesel fuel as an ignition source, the flame flow around the bluff body propagating as a crosswind at speeds of 0.8-2.4 m/s was studied. The results showed that the fluctuation of the mass loss in a rising period decreased. A new flame spreading phenomenon of continuous-flow around-broken-retract appeared. The average spreading rate affected by the bluff body had a quadratic nonlinear relationship with the intensity of airflow. A prediction model of the flame drag length for the rectangular pool containing a bluff body was established. In addition, there were two vortices near a bluff body that were symmetrical and flowed in opposite directions. The temperature at the standing vortices reached a maximum of approximately 260 degrees C. At the same time, the vortices presented the characteristics of periodic formation and shedding with an interval of approximately 3.6 s.

Automated summary

In this experimental study, it was found that ship cabin equipment affects the combustion characteristics of flames during a fire, leading to a new flame spreading phenomenon. The spreading rate of the flames had a nonlinear relationship with the airflow intensity, and a prediction model for flame drag length was established. Additionally, vortices near a bluff body exhibited periodic formation and shedding with a temperature reaching approximately 260 degrees C.