calculation of calibrated diaphragm flow

[TECNOMODEL]

I can't find the correct formula
I have a calibrated orifice on a pressure duct, knowing the orifice area and fluid pressure (oil) how to calculate the flow?

 

[volaff]

I can't find the correct formula
I have a calibrated orifice on a pressure duct, knowing the orifice area and fluid pressure (oil) how to calculate the flow?

to calculate the flow rate, by memory, you need the fluid speed, note the area.

 

[TECNOMODEL]

It's a fact that I don't have, by the way, impossible to measure.
the system you indicate comes from bernoulli, but I have a pressure duct from which "spillo" an oil quota.
in the duct I have no fluid speed when I have the pressure, it seemed to me that it was also calculable with area and pressure.

 

[mambo1988]

by applying bernoulli (energy conservation) you should be able to obtain the output speed from the hole.
speed output from the hole = root (2*conducted pressure/density)
volumetric flow = speed*section*coefficient of contraction

 

[Kaji]

Perhaps the forum treats the topic more pertinently,

 

[TECNOMODEL]

by applying bernoulli (energy conservation) you should be able to obtain the output speed from the hole.
speed output from the hole = root (2*conducted pressure/density)
volumetric flow = speed*section*coefficient of contraction

I was also thinking about bernoulli.
What measuring unit would you use?
What do you mean by contraction coefficient?

 

[TECNOMODEL]

Perhaps the forum treats the topic more pertinently,

It doesn't seem appropriate to solve this problem.
How would you apply it?

 

[meccanicamg]

formulas related to the manometric sockets with calibrated hole follow the rule of the incomprehensible fluid if we are talking about oil. therefore follow the following formula:As you can see, you always have a pressure variation between the two points...and then a sort of fluid speed indication.

for a compressible real gas, the question becomes more complex.

 

[TECNOMODEL]

formulas related to the manometric sockets with calibrated hole follow the rule of the incomprehensible fluid if we are talking about oil. therefore follow the following formula:View attachment 48843As you can see, you always have a pressure variation between the two points...and then a sort of fluid speed indication.

for a compressible real gas, the question becomes more complex.

Good, I went close.
I lose a little on that flow coefficient:frown: the efflux coefficient to calculate it from where you take it?
What else is that pressure?

Thank you very much

 

[mambo1988]

Good, I went close.
I lose a little on that flow coefficient:frown: the efflux coefficient to calculate it from where you take it?
What else is that pressure?

Thank you very much

excellent [MENTION=21735]Mechanical[/MENTION], I should take the fluid mechanics notes to get that formula. [MENTION=48249]technomodel[/MENTION] However in the first approximation you can consider alpha =1 (alpha takes into account the reality of the fluid).
delpa p is the pressure change between the two environments you are considering. (e.g. p reservoir= 7 bar p environment = 1 bar in absolute terms delta is simply 6 bar)

greetings

 

[TECNOMODEL]

ok delta p, but why multiplied also by p? (√ 2*p*δp)

 

[mambo1988]

ok delta p, but why multiplied also by p? (√ 2*p*δp)

p=rho indicates the density:finger:

 

[TECNOMODEL]

time does not help:redface:
Thank you very much

 

[TECNOMODEL]

I don't get the accounts back from experimental checks.
My orifice is not really circular but it is a circular sector. I calculated the equivalent to the sector area.
the value that I echo however is different from the measured test counter.
my orifice corresponds to a ø 0.7, we use oil with density 873 kg/m3, delta p is 79 bar.
the value of p in which unit of measure should be expressed?

 

[meccanicamg]

the delta p in pa. there is written all in my formulas, including unit of measurement in brackets square.

 

[TECNOMODEL]

You're right, I'm sorry.
I had seen all the others and I had escaped that. I know that if they don't come a little vacation:frown:

 

[meccanicamg]

It's normal... too... too... too... too... .

here in briance: there, sü, neem....fá balá i man
translated: come on, let's go... let's dance the hands

But come on and give you... some castronata la ai fa.

 

[TECNOMODEL]

What's wrong?

 

[Stan9411]

mistakes that sqrt( density * pressure) will never make a speed.... if anything is sqrt(pressure/density):

(kg*m/s^2)/m^2; rho = kg/m^3 .

make the simplifications and then the root and you will return m/s.

 

[Stan9411]

of course if you multiply for the area of your hole you get your volumetric flow rate: m^3/s or lt/s