Effect of orifice size on water jet force
 

Bit of a tenuous link to the CFD forum this, as I am not currently modelling it (Though I may in future)

Please can you refresh my memory in fluid mechanics as its been a while:

I am working on a job in wastewater treatment which involves rotating arms which distributes water onto filter media (Trickling Filter).

The rotation of the arms is driven by the force of the water jets exiting orifice holes along the length of each arm.

Would a decrease in the diameter of these holes reduce the force of the water jet, and hence reduce speed, or the other way round?

Like I say, I don't think the question is that hard, but just cant stop thinking about it.

Hope you can help

have a look at the book of White, you will find many examples

https://docs.google.com/file/d/0B9Jt...Zjg/edit?pli=1