Flame Spread Behaviors over Inclined Polyethylene Insulated Electrical Wire with AC Electric Fields

The effect of applied electric fields on the characteristics of flame spread along slanted polyethylene (PE) insulated electrical wire was investigated experimentally by varying the AC frequency and voltage. The result showed that the spread rate of downwardly spreading flame decreased in increase of voltage and frequency, while that of upward flame spread rate exhibited complicated behavior with applied voltage and frequency. Downwardly spreading flame size became smaller in increase of applied voltage and frequency and leaned toward burnt side. When flame spread upwardly, the flame size experienced large variation with applied voltage and frequency and leaned toward unburned side. Based on flame shape and the slanted direction of flame, the flame spread rate could be explained by thermal balance mechanism.