Mass flow rate

https://photos.travelblog.org/Photos/184577/616417/f/6183163-Drill_bit_from_the_oil_museum-0.jpg

Hi,

I was wondering if theres a way to define the mass flow rate at the nozzle entry in a drill. Theres a picture showing the nozzle position (the holes are the nozzle)

It would be extremely helpful, If anybody can give a lead on how to do this.

Thank you
Regards,
Ananthakrishnan