Abstract: To explore the effectiveness of transitional jet in firefighting and rescue operations, this paper conducted experiments to study the fire control area of transitional jet in a 4.70 m × 2.66 m room by changing 3 factors of transitional jet as jet impact point, jet pressure, and jet angle. Experiments showed that transitional jets are difficult to effectively control the room between the jet inlet and the impact point. When the jet angle is 60°, adjusting the jet pressure is difficult to change the distribution of the jet in the room, and the scattered water flow of the jet is mainly concentrated within the depth range of 4.14~4.70 m in the room. When the jet angle is 70° and the jet pressure is 0.20 MPa, the scattered water flow of the jet hitting the window eyebrow has the largest fire control area, which is 68% of the total room area. When the jet angle is 80° and the jet pressure is 0.25 MPa, the scattered water flow of the jet hitting the window eyebrow has the largest fire control area, which is 72% of the total room area. Among the 3 influencing factors of experimental control, the jet angle has the greatest impact on the fire control area.

Key words: transitional fire attack, strike point position, jet pressure, jet angle, fire control area