Abstract: Taking vertical combustible material PMMA as an example, the FDS software was used to study the influence of spray characteristic parameters (spray flow, spray angle) to the vertical temperature field under vertical orthogonal design.The visual analysis method, analysis of variance method and factor index were used to study the rules of influence. The experimental results showed that, increasing the spray flow and the spray angle can effectively suppress the material combustion; the suppression effect caused by increasing the spray flow is greater than the suppression effect caused by increasing the vertical spray angle or horizontal spray angle.

Key words: vertical material combustion, water spray, FDS simulation, orthogonal test