Try it now:

http://www.lmnoeng.com/PipeDuct.htm

I lost it...

I have this formulae from a nice fellow from TechRep, but I lost how he came up with the numbers.

Maybe some guru can look at this, and point out what I'm missing?

The formulae is S= (Qm x Gl) / (N x D^2 x Fa x Fm x Fc x Fp x Gf^.5 x Hm^.5)

S: I don't know, I forgot!
Qm: flow (in gph)
Gl: base specific gravity
N: conversion constant
D: line ID
Fa: temp corr
Fm: manual correction
Fc: Rd corr
Fp: flow comp ratio
Gf: flow specific gravity
Hm: differential pressure (in inches wc)

The data I originally gave him was:
flow rate: 250 gph
line ID: 3/4 in.
outlet: 3/16 in. or 1/8 ?
fluid: water


Here are the values he used to determine the pressure drop (from the worksheet he faxed me):
S = 0.03957
Qm: 250
Gl: 1.0
N: 340
D: .75
Fa: 1.0
Fm: n/a
Fc: 0.99
Fp: 1.0
Gf: 1.0
Hm: ?

Fc comes from a graph. Hm was calculated to be 1113" wc, but I think it was meant to show the inlet pressure, because he calculates an 80% pressure drop to come up with an outlet P of 890" wc.

but what is "S", and how did he come up with it?


Anyone? Help! :cry:

:D I googled anf found this

Happy happy joy joy

Hey Ben,

Can you point me in the right direction for calculating velocity for a given nozzel? How much velocity would be coming from typical pump with one foot of hose?

This is a simple calculation, if you know the flow rate, and the outlet diameter.

As for your foot of hose, you need to calculate the pressure drop, and match it with the pump's PQ curve, to determine the flow rate.

Can you take it from here, or should I go on?

I can take it from there. Search and google should work if I get hung up. Thanks! I just hate math when it comes to physics.:rolleyes: Programming I'm good to go.

LiquidRulez: clear your PM box so I can reply!!!

I have none in there and I keep getting emails about clearing them up....that Ive reached my limit.:confused:

I sent procooling an email. hopefully they can get it all straightened out.

Till then ben..... just email me replies dude.

Later

PM me an e-mail addy, will ya? Your PM box is still registering as full.

I tried PM'ing Joe, but his box is full too!

May I throw this variable into the equation...if you have a 1/8 inch hole and wish to increase the pressure but have the same amount of water flow.

Would you not oblong the hole???

In other words...stretch the hole out sideways...maintaining the same size opening...just a different shape.

This type of Nozzle is used for carpet cleaning so that a relatively close pressure and water flow is produced across the entire range. Not much variance from the middle to the sides

If you have 150psi in the middle you will have a slight drop at the sides.

From what I understand...the cpu runs hotter in different sections...so by using an oblong hole would you not have a better chance at supplying pressure and more flow of the water water to all the parts that need it?


Another example the spray wand at the carwash. This is done with an oblong hole. Some of these nozzles supply 1000-1500psi.

Tuff

:shrug:

hey guys. I'm not sure if this is still relevant, but nozzle design angles were being discussed further up. I was just reading about similar things for air ducting. An abrupt size change such as an orfice will kill flow and create turbulance. A slow taper is much better, but uses valuable space. 40 degrees is the maximum safe angle to reduce a nozzle at to maintain laminar flow. (when 0deg=no change, 90deg=orfice)

There is a vast difference between an impingement nozzle used with water versus air.

yes, it will kill flow but increase velocity, as long as the pump can handle the extra head from the nozzle,because of the same amount of flow trying to fit through a much smaller opening basically.

I did some research into this. Oblong or obleque is the best shape. Followed by triangle, square then circle.

http://www.ecs.umass.edu/mie/faculty.../sae971597.pdf


that should help you guys out