Visualization of Fuel Jet in Conditions of Highly Preheated Air Combustion

Numerical study of fuel temperature influence on single gas jet combustion in highly preheated and oxygen deficient air

“…Fuel nozzle is placed on the wall in a cross-flow to the main flow of oxygen deficient and preheated air. In a way similar to that during the experiments presented by Lille et al [6], the preheated air was mixed with nitrogen in order to decrease oxygen concentration. Variables chosen for numerical studies are fuel injection temperature, oxygen concentration, and temperature of the preheated air.…”

“…When analyzing the literature of the subject, it is well seen that the study of a single fuel jet allowed explaining and measuring many unique features of the HiTAC. For example, experimental studies of single fuel jet were performed by Hasegawa et al [1], Gupta et al [3,4], Kitagawa et al [5], Lille et al [6] and Blasiak et al [7]. Numerical studies focused on studies of the structure of flame and different mathematical models using well-known general-purpose codes as FLUENT [8][9][10] and CFX [11].…”

“…Since the nozzle is not cooled, the fuel temperature is elevated. Temperature of the fuel jet, as high as 500 K, was measured in the experimental single flame furnace, which is described, for example, by Lille et al [6] and Blasiak et al [7]. Therefore, influence of the fuel elevated temperature on results of mathematical modelling should be verified.…”

Prediction of Flame Liftoff Height of Diffusion/Partially Premixed Jet Flames and Modeling of Mild Combustion Burners

“…The contours of stoichiometric fuel mass fraction and k=e based fluid time scale of 2, 3 and 4 ms are plotted as shown in Figure 4 for the case of propane fuel at a jet Reynolds number of 15,500. For the case of highly preheated and low O 2 mass fraction coflow, it has been observed that the overall temperature rise across the reaction zone is about 200-300 K (Lille et al, 2000). It is very difficult to identify the exact flame location in the combustion zone.…”

“…Therefore, the present computations are carried out to predict the flame liftoff heights and compare the predictions with a select set of experimental results taken from different sources (Donnerhack and Peters, 1984;Kalghatgi, 1984;Rokke et al, 1994;Lille et al, 2000;Cabra et al, 2002) expecting the comparisons to be within the AE5% of the experimentally reported flame liftoff heights. Figures 5 and 6 show the flame liftoff height predictions carried out with a constant time scale of 8.5 ms. Flame liftoff heights are overpredicted at low velocities and under-predicted at high velocities-near the blow-off limit.…”