droplets and momentum transfer.

mic

Hi guys. I experienced this strange thing: i run a spray simulation with 720 drops, all the options under droplet conditions activated (ie momentum transfer, heat transfer, mass transfer) in the standard way, but in the track file i see that the mass of the parcel remains constant. It changes only the dimension of the track file (there are almost 5000 rows, with only momentum trasfer i had 65000 and more rows..), and turning off the mass and heat transfer options seems to not have any effect (on the mass, almost)... Moreover, with only momentum transfer i had in the "current post file" tracks displaying mode the whole 720 parcels, but now with both mass and heat transfer i have loaded only some parcels, since other are "evaporated or otherwise disappeared", and this could appear to be normal... but is it normal that the parcel's mass remains costant while its diameter is dropping down ? And what could signify this "otherwise disappeared?"