  This paper presents a flame-height correlation for laminar to
transition-to-turbulent regime diffusion flames. Flame-height measurements are
obtained by means of numerical and experimental studies in which three high
definition cameras were employed to take frontal, lateral and 45{\deg} angled
images simultaneously. The images were analysed using an image-processing
algorithm to determine the flame-height through indirect measurement. To locate
an overall chemical-flame-length, numerical simulations were conducted with the
unsteady Reynolds-Averaged Navier-Stokes technique. The eddy-dissipation model
was also implemented to calculate chemical reaction rate. The experiments show
that this proposed correlation has an adjustment variation of luminous
flame-height for the laminar regime of 16.9%, which indicates that, without the
use of the intermittent buoyant flame-height correlation, it globally best
represents the flame-height in this regime. For the laminar and
transition-to-turbulence regime the adjustment variations are 5.54% compared to
the most accepted flame-height correlations, thus providing an acceptably good
fitting. The numerical results show that the proposed range for the
chemical-flame-length is located between the luminous and flickering flame zone
compared to the experimental flame images. These results agree with the
chemical length zone reported in the literature. Therefore, the correlation can
be used for laminar and transition-to-turbulent combustion regimes.
