Number of streams in particles injection

- June 19, 2020 at 1:12 pm
  
  Luigi0
  Subscriber
  
  Hi there, in "set injection properties dialog box", when I choose "group injections" , I have to set the number of streams, but I need a clarification about this concept. What do they represent?
  
  If I want to inject 1000 particles, i have to set 1000 streams?
  
  Thanks
- June 19, 2020 at 4:27 pm
  
  Rob
  Forum Moderator
  
  Remember you're injecting parcels not particles. 1000 streams will give 1000 parcels each of 1/1000 of the injection mass. That may be a touch excessive.
- June 20, 2020 at 1:12 pm
  
  Luigi0
  Subscriber
  
  Thanks.
  
  So if I decrease the number of parcels, I am not decreasing the number of particles because this is related to the injection mass. Is it right?
- July 2, 2020 at 10:48 pm
  
  ai0013
  Subscriber
  
  Parcels are the minimum "solvable" items in fluent, they "represent" particles with similar characteristics. Based on your current mass flow rates, fluent will split that rate into your specified number of streams. If you input 1kg/s with 10 streams, then each stream will inject 0.1 kg/s. Now, a discrete mass flow rate = # particles / sec * mass of particle. I think you can see from here what will happen to your # particles.