Numerical studies on an accidental flashfire at a water fun park by FLACS software

A severe accidental fire with ‘explosion’ resulting from spraying coloured corn flour powder occurred at a water fun park in Taiwan. The possible fire scenarios were studied in this paper using Flame Acceleration Simulator(FLACS). Environmental conditions including wind action and solid boundary conditions were deduced based on government fire investigation and video records, and were used as the input parameters in simulation. Simulation results indicate that upon ignition of the sprayed powder, the maximum overpressure in the open space was only 0.03 bar gauge, with a dust flash fire generated without having an explosion. These environmental conditions or parameters and the simulation results together would give a fire scene that agrees with the accident observed, indicating that appropriate environmental parameters had been identified. Therefore, CFD simulation with carefully selected parameters can be used to reproduce explosion scenarios and to identify key factors in supporting accident investigations.