If you want a fine spray from a pressure source of say 100 PSI through an opening .03", how will the length of the .03 passage way effect the liquid (say water or gasoline) expelled? Does a longer ...
If you are working with a true solution, spray tips will not affect the liquid. If you are spraying a near-liquid emulsion the orifice must be 2.35 times the maximum size of the globules.
The Pearson Table shows the easiest calculation by viscousity for standard spray heads in different applications.
As to the spray heads themselves: you will find that pattern, angle of deflection, and angle of incidence, will dictate your selection of spray nozzles. Those used in airless paint sprayers have X and Y axes: the X axis is the width of the spray column and the Y axis is the angle of spray projected from the gun.
Fuel spray nozzles (e.g. diesel fuel injection systems) inject a non-directional "cloud" of atomized fuel into the combustion cylinder. Fuel nozzles in flame-retention fuel oil burners deliver their fuel in a cone of large droplets in a specific angle cone and the injectors use a "tribulator" to direct the fuel into a centrifugal pattern for efficient combustion.