Infrared thermographic evaluation of flame turbulence scale

Evaluating flame turbulence scale in diffusion combustion of diesel fuels

“…In the zone where burning declines, the turbulent eddies disintegrate. Since the experimental and numerically modeled values of turbulence scales of gas fired flames are in good agreement, the approach described in [7] permits the evaluation of turbulence scales in natural flames. Temperature pulsations are related to turbulent flame flow, and the characteristic temperature spectrum frequencies are affected by the turbulent eddy scales.…”

“…The use of IR thermography for the evaluation of flame turbulence scale was described in details for several fuels [7]. Diesel fuel of which mass varied from 20 to 50 grams was diffusively burnt out in a 0.15 m-diameter container.…”

“…Next, using the method of determining turbulence scale by temperature spectra described in [7], the following scale estimate was obtained by considering a single much used frequency: b ± b = 0.025 ± 0.0055 m; the respective non-dimensional flow characteristics were calculated: Ri t = 0.1846 and F r t = 5.4183.…”

“…Flame turbulence scale can be experimentally evaluated by analyzing IR thermograms of flame jets obtained in narrow spectral bands corresponding to the spectra of some marker gases (water vapor and CO 2 ), as shown in [7]. In the same research, by assuming the similarity of pulsations of hydro-and thermo-dynamic parameters, the relationship between turbulence scale and characteristic frequencies of temperature pulsations in flames was mathematically investigated.…”

“…In this paper, we propose a mathematical model of diesel fuel combustion and compare the theoretical results with the experimental results obtained by thermographically estimating the size of temperature non-homogeneities and turbulence scale. Methodical aspects of this research were reported in [7].…”