Flame Spread over Liquid Fuel on a Water Layer-Basic Research on Tsunami Fire

The purpose of this study is to reveal the flame spreading mechanism of tsunami fire. But the mechanism of tsunami fire is so complex that we couldn’t assess qualitatively. So the basic research on tsunami fire is needed. As a first step, we did flame spread experiment on only liquid fuel and liquid fuel/water layer under static liquid fuel. We measured flame spread rate. As a result, fuel thickness is in range of 5 - 15 mm, and flame spread rate over only liquid fuel is faster than liquid fuel/water layer’s at same fuel thickness. To reveal the gap of the flame spread rate at same liquid fuel thickness, we visualized current distribution by PIV and thermal boundary layer by shadowgraph method. By these results, we revealed that the thermal characteristic length is longer and the current characteristic depth of liquid fuel/water is deeper than that of liquid only fuel.