Multi-Objective Optimization of Three-Phase Jet Fire Monitor Nozzle Based on Kriging and NSGA-II

The nozzle, converting pressure into kinetic energy, is the key component of fire extinguishing equipment, and its structure seriously affects the jet performance of fire monitors. In this study, the three-phase jet fire monitor (TPJFM) nozzle is taken as the research object, and the primary structural dimensions of the nozzle’s internal flow channel are considered as design parameters. A multi-objective optimization approach is employed to minimize the average turbulent kinetic energy at the outlet of the nozzle internal flow channel and the pressure drop between the inlet and outlet of the nozzle internal flow channel by integrating the Kriging surrogate model and NSGA-II. The research results indicate the pressure drop between the inlet and outlet of the nozzle internal flow channel decreases by 3.48%, and the average turbulent kinetic energy at the outlet of the nozzle internal flow channel reduces by 29.38% after optimization. The flow velocity distribution at the outlet of the internal flow channel of the optimized nozzle is more uniform, with an increase in jet range by 6.25%. Reasonable optimization of nozzle structure can significantly improve jet performance, and this method can provide a reference for designing nozzle structures.