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.