Experimental study on the diffusion patterns of novel clean fire extinguishing agents in concealed areas of civil aircraft cargo compartments

This study constructs a 1:1 physical platform simulating the concealed areas of an Airbus A330-300 cargo hold and conducts experiments using handheld onboard fire extinguishers to investigate the diffusion characteristics of the novel clean extinguishing agent and its concentration distribution in concealed spaces. The results indicate that the extinguishing agent exhibits a top-down diffusion trend along the vertical axis. Along the longitudinal diffusion direction, the agent concentration is highest near the injection point and gradually decreases with increasing distance from the source. During diffusion, the agent struggles to ascend to the upper concealed spaces. By directing the spray toward obstructing equipment or structures, a portion of the agent can penetrate shielded corners.