Ohnesorge number
The Ohnesorge number for a 3 mm diameter rain drop is typically ~0.002. Larger Ohnesorge numbers indicate a greater influence of the viscosity. This is often used to relate to free surface fluid dynamics such as dispersion of liquids in gases and in spray technology. In inkjet printing, liquids whose Ohnesorge number is less than 1 and greater than 0.1 are jettable (1<Z<10 where Z is the reciprocal of the Ohnesorge number).
Applications
It is defined as:
formula_1
Where
* "μ" is the dynamic viscosity of the liquid
* "ρ" is the density of the liquid
* "σ" is the surface tension
* "L" is the characteristic length scale (typically drop diameter)
* Re is the Reynolds number
* We is the Weber number