Single droplet impact

Comparing this splashing criterion to that derived by Stow and Hadfield13961 for single droplet impact (Eq. 44b), the scaling... 

Secondary atomization upon spray impact can be generated by diverse mechanisms. Models have been devised from experiments with single droplet impacts, which give the number, velocity, and direction of secondary droplets. Incorporation... 

Figure 5.12. Comparison of spreading behavior of a single droplet at different initial impact velocities Re = 9530, 19060, 38115 We = 530, 2119, 8474 e/D0 = 0 flat), e/D0 = 0.33 and XID0 = 2.8 non-flat).(Reprinted from Ref. 389. 1995, with kind permission from Elsevier Science Ltd., The Boulevard, Langford Lane, Kidlington 0X5 1GB, UK)...

Therefore, the following discussion aims to explain how droplets behave on smooth, imstructured substrates, which have been either coated or cleaned, and why certain phenomena might occur. After discussing droplet impact, two types of droplet will be considered. The first are droplets of solvent, which may also describe droplets of solution below the solution s critical concentration. The second are suspension droplets that can describe droplets of solution after the critical concentration has been exceeded and are useful in explaining droplets formed from nanoparticle ink. Besides single droplets, large arrays of droplets, such as lines and films, will also be discussed. 

Single Droplet Impingement onto Non-heated Dry Surfaces The Impact Regimes... 

All of the droplets then hit the ground. In cascades with high liquid mass flux densities the droplet impact speed may considaably exceed the terminal velocity for a single drop. Again the number and size of smaller secondary droplets formed on impact depends on the surface tension, impact speed and the nature of the impact surface ie wetted solid or deep liquid. 

Inertial impaction is the method of choice for evaluating particle or droplet size delivery from pharmaceutical aerosol systems. This method lends itself readily to theoretical analysis, ft has been evaluated in general terms [39] and for specific impactors [40]. Inertial impaction employs Stokes law to determine aerodynamic diameter of particles being evaluated. This has the advantage of incorporating shape and density effects into a single term. 

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