Particle size and distribution are related to the size
of the droplet s an d their size distribution. Hence,
success ful prediction of dro plet size enables one to
control the powder propert ies as desired .
The mean size of drop let repres ents a single v alue
that charact erize s the whole spray distribution. This
value, toget her with the size dist ribution, defines the
spray charact eristic s. Many pa pers have app eared on
the subject of drop size predict ion. The so-called Sauter
mean diameter seems to be the most suit able mean
value to ch aracterize the droplet cloud toget her with
the size distribution. This is defi ned as the ratio of the
total droplet volume to the total droplet surface [23] ;
that is,