Experimental investigation of spray characteristics in model combustor

Fuel spray characteristics in a swirl-cup model annular combustor are investigated. In order to better quantify and distinguish the diameters and numbers of the fuel droplets, and their size distributions, image-processing technologies are applied for raw images of fuel spray field. These techniques include gradation processing, edge detection, smooth disposal, outline extraction and picture disposal. Experimental results show that the proposed image-processing technologies demonstrate an effective method for the characterization of the fuel spray field in the studied gas turbine combustor. Parametric studies were also conducted to investigate the influences of different inlet parameters such as inlet air temperature, inlet air flux and fuel air ratio on the spray field. It was found that the fuel atomization becomes better with the increase of inlet air temperature and fuel air ratio; however, the change of inlet air flux has a minimum effect on the spray field.