Optimal Detector Placement for Fire Smoke Detection in Ventilated Aircraft Cargo Compartment

Detector placement design is a key technical problem in the design of fire smoke detection system of aircraft cargo compartment to fulfill the one-minute rule. Previous studies already revealed that ventilation has a remarkable effect on the transmission and detection of fire smoke in the aircraft cargo compartment, but the optimal detector placement in ventilated aircraft cargo compartment still needs a more detailed attempt. In this paper, first, a CFD numerical model of fire smoke of DC-10 ventilated aircraft cargo compartment is built, the CFD model is validated using FAA experimental data, and simulation and experiment are conducted based on a full-scale cargo compartment mock-up with a single vent to reveal the fire smoke spreading and the optimal detector placement under ventilation condition in detail. Results show that ventilation will substantially inhibit the vertical upward diffusion of fire smoke, thus delaying the time for smoke to reach the ceiling of the cargo compartment. The fire source beneath the vent is the most unfavorable position of fire source in the detection system design. For the full-scale cargo compartment mock-up, the optimal detector placement is to place four detectors in the four corners of the cargo compartment.