# How to quantify a misty-ness of a spray?

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The above are three spray models. The latter one is fuel injector spray. Consider I have a closed container which I can increase its pressure by any means such by pumping, reduce the volume like with piston, etc, and on the bottom side there is a small opening area a (i.e, a nozzle with diameter 1mm). My question is: How do I quantify the haze-ness/misty-ness or the level of atomization of that spray, including the size of the haze/mist it produced?

Note: The background of my question is that the most atomized the fuel in the combustion chamber the better the combustion, then I searched about fuel injector. But then I realized that I also frequently spray my garden to kill the insects that ruin the plants, and also in many occasions I used spray perfume or deodorant or room fragrant, and so on. There are many applications. In my observation, the spray output are different, more or less their output form are represented by those three pictures.

• Combustion is also controlled by spray direction and pattern, not only the mist particle size or droplet size. Also, the pressure from your garden sprayer has little to do with the pressure from the injector - your garden sprayer is about 30 to 50 psi. An injector is around or exceeds 1000psi - in fact it can inject liquid into your bloodstream and can kill you. Jan 23, 2023 at 17:25
• Yes, of course. But the less atomized the fuel could lead to misfire for diesel engine as the pressure inside the combustion chamber is not enough to create heat to burn that diesel fuel. In gasoline case, the less atomized the fuel make less force as not all the fuel is burnt during the explossion. Jan 24, 2023 at 16:09
• From my understanding and from my observation, pressure we apply is very related to the nozzle size and the type of liquid we use. For the same spray tube, the atomization level will be different for diesel, gasoline, fresh water, and other liquid substance like we use with our parfume. Jan 24, 2023 at 16:12
• So check out water sprayed at 1500bar or 3000bar... Jan 24, 2023 at 16:27