Physical Properties and Drop Size

In the process result of area generation or dispersion, the most important physical property for low viscosity fluids is the interfacial tension. This is the force at an interface between immiscible fluids liquids with liquid or liquids with gas 

When dealing with the contacting of liquid in continuous gas flow in static mixers, one thinks in terms of liquid film flow on the mixer surfaces and droplets being formed as the liquid film is sheared off the mixer blades. The total interfacial surface is a combination of film plus droplet surface. Film flow is well defined and equal to the mixer plate surface area and is often used as the contact surface area for calculation of mass and heat transfer capacity. Mixers with high surface/volume ratios are most often the preferred design. 

1 Turbulent Flow Dispersed Phase Drop or Bubble Size. The 

Here K is different for various mixers and the form does not include all the density, viscosity, and concentration effects. For fluids with a low density 

Additional terms are often included to take into account dispersed phase viscosity and coalescence due to holdup. They usually depend on the volume fraction of dispersed phase  

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