ABSTRACT
The effect of different depth-width ratios, α, on the flame spread over molded polystyrene (EPS) at the central place ignition was studied. The variation laws of characteristic parameters such as flame structure, flame height, flame spread rate, flame temperature and mass loss rate were analyzed. The experimental results show that at the central flame spread, the extinction, re-ignition, and re-burning were found for the upward flame except at α = 1.5, while the downward flame didnot have these phenomena. At α = 1.5, the stability of upward flame spread was the best, as the extinction didnot occur, and the flame spread rate was the fastest. When α <1.5, the extinction of upward flame could be sorted to flame instability, while when α >1.5, the extinction could be attributed to the more hot smoke effect. If the average flame height of upward increased, the average flame height of downward decreased, and vice versa. Inner flame pressure model was built, which could better explain the characteristics of mutual inhibition between upward and downward flame heights.
KEYWORDS
PAPER SUBMITTED: 2021-10-26
PAPER REVISED: 2021-12-27
PAPER ACCEPTED: 2021-12-29
PUBLISHED ONLINE: 2022-02-05
THERMAL SCIENCE YEAR
2022, VOLUME
26, ISSUE
Issue 5, PAGES [4377 - 4389]
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