liquid flow through a nozzle to atmosphere

[rppearso]

How can the orifice size be calculated through a piping segment where the end of the pipe is a nozzle that discharges to atmosphere. The pressure right at the nozzle is not going to be atmosphereic so without knowing the downstream pressure or the mass flow how can you determine what an upstream orifice will need to be sized to prevent the over pressure of a spec break in the middle of the piping that goes to the nozzle. I am going to keep digging through perrys and searching online, I am almost thinking I would need to have that non 0 downstream pressure or the velocity of the water jet as it exits the but of course that pressure and velocity is going to change as I change the RO diameter.

 

[rppearso]

never mind I figured it out.

 

[takiro]

so go ahead and share us

 

[CbusPaul]

Takiro,

I don't think rppearso will be able to share anything with you anytime soon. I haven't looked at fluids in a long time so maybe one of the other ChE's will stumble on this and answer your question.

Cbus

 

[MGX]

Use bernoulli's equation and assume the nozzle exit pressure is either zero or atmospheric depending on your reference point of gauge or absolute. Of course bernoulli's will not yield any friction losses but should suffice for most nozzles.