The atomization characteristics of a commercial spillback hydraulic nozzle were investigated in terms of droplet sizes, velocities, trajectories and spray angles. To replicate the fuel spray of a commercial auxiliary marine boiler, an experimental setup was designed and used to atomize water-glycerol solutions with various viscosities. Droplet size, velocity, position and shape were obtained with a novel pulsating LED backlight imaging system that employs a CCD camera to capture pairs of frames with a delay as short as 1 μs from one another. The overall spray characteristics of the nozzle and distributions for droplet size and velocity were examined for the operating conditions currently used in the burner and by varying three parameters: pressure drop, flow rate through the nozzle and liquid viscosity. Results include droplet size and velocity distributions in different spray regions, a description of the influence of each varying parameter on global indexes such as the Sauter Mean Diameter and a comparison with traditional correlations for pressure swirl nozzles.
|Journal||Experimental Thermal and Fluid Science|
|Number of pages||8|
|Publication status||Published - 2020|