“…A temperature contour from IR images can also be used as a flame boundary. Cumber determined that the visible boundary is equivalent to a heat flux of 40 W/m2 (Cumber and Spearpoint, 2006), Upatnieks a temperature contour of 600 K (Upatnieks et al, 2004), and Palacios 800 K (Palacios and Casal, 2011). In this study, both IR and CCD camera were used to visualize the jet fires, similar to Palacios (Palacios and Casal, 2011).…”