ID 7

Development of Spray Transmission Efficiency applied to Planar Surface Area

 

Abstract:

The transmission of material from a spray nozzle source toward a target or through a medium takes place in many industrial applications with a wide variety of materials. The efficiency with which the sprayed material, fluid in this case, moves downstream, and the associated distribution and possible loss of material is useful to understand and quantify. This work defines the spray transmission efficiency ($\eta_T$) and applies this metric to analyze the development of various spray types in the context of total planar spray surface area across a range of axial spray distances. Each investigated spray is commonly used in many industrial applications, covering hydraulic full cone and flat fan sprays, as well as air-assisted nozzles with external- and internal-mix arrangements. Furthermore, while the tests are conducted spraying water at ambient temperature, a simulated dataset in which the spray quantity is decreasing with distance allows analysis of the in-flight changes within a spray in the presence of vaporization or environmental interaction. The spatial development of each spray, and the associated transmission efficiency, demonstrates a quantifiable method to assess the change in spray surface area due to break-up, dispersion, or vaporization. Specific nozzle types are identified to promote surface area generation. Strong correlations between droplet size and plume concentration with spray surface area shows that these characteristics govern the amount of surface area.