# Pressure and temperature drop through orifice

• srs22
In summary, the individual is seeking help with finding software to simulate and obtain results for pressure drop through an orifice plate. They have tried ANSYS v10 but did not understand how to use it properly. They are looking for open source software as ANSYS 12 and 13 are too costly. The person also shares some parameters for the orifice plate and is seeking help with finding the outlet pressure, velocity, and temperature drop. They mention theoretical equations and online calculators that can be used, but they are looking for a software that can simulate and present the results. Another individual suggests looking at ASME PTC 19.5 for reference. The original person also mentions the need to compare theoretical and computer generated results and considers using AN

#### srs22

Hi,

I am currently trying to do a project for my final year in engineering.I have not been able to find any software that's helping me in simulating and obtaining results for pressure drop through an orifice plate.

i have tried the fluid option in ansys v10 dinn't understand how to use it properly its giving stress concentration due to fluid pressure than pressure drop through the orifice plate

is there any open source software that will help,ANSYS 12 and 13 are too costly

orifice plate:
1}inlet dia is 1cm
2]outlet is 0.5 cm
3]inlet pressure is Atmospheric 101.3 Kpa
4]inlet velocity is 30km/hr or 8.3m/sec

i need to find outlet pressure,velocity and temperature drop from inlet to outlet

theoretically Bernoulli's principal can be used but either V(outlet) or p(outlet) is required

any help is appreciated,

THank you :)

Flow through an orifice is calculated in various ways depending on whether the fluid is gas or liquid and whether it might be choked flow. Equations can be found here:
http://www.air-dispersion.com/usource.html

Equations and an online calculator can be found here:
http://www.lmnoeng.com/Flow/SmallOrificeGas.htm

Regarding temperature drop through an orifice, we generally assume the pressure drop is isenthalpic. To get fluid properties for real fluids you should use a fluids properties database. Note that a temperature drop won't be predicted for an ideal gas or a perfectly incompressible fluid.

Q_Goest said:
Flow through an orifice is calculated in various ways depending on whether the fluid is gas or liquid and whether it might be choked flow. Equations can be found here:
http://www.air-dispersion.com/usource.html

Equations and an online calculator can be found here:
http://www.lmnoeng.com/Flow/SmallOrificeGas.htm

Regarding temperature drop through an orifice, we generally assume the pressure drop is isenthalpic. To get fluid properties for real fluids you should use a fluids properties database. Note that a temperature drop won't be predicted for an ideal gas or a perfectly incompressible fluid.

so theoretically using those formulas i can solve and get my required answer..but is there a software that will help me simulate this and show it as a presentation using software like ansys or some thing similar

I'm sure there's software that can do it but I'm not familiar with it. Just seems like a lot of effort to use a CFD software package when it can be done in seconds on a spreadsheet.

Try looking at ASME PTC 19.5 (it should be in your college library).

thanks for the replies :)

if i am getting a pressure drop from 101.3Kpa to 37.5Kpa
and increase in velocity from 8.33 m/s to 33.33 m/s

what kind of temperature drop can i expect ?

i looked through Google,dint get satisfactory results..i saw some charts of pr density vs temperature i couldn't infer much

Q_Goest said:
I'm sure there's software that can do it but I'm not familiar with it. Just seems like a lot of effort to use a CFD software package when it can be done in seconds on a spreadsheet.

i have to compare theoretical and computer generated results to prove what i have done is right,so a simulation of flowing fluid will be and changes in temperature,pressure,velocity has be shown...i will try using Fluid option in ANSYS 10 or i have to learn how to use fluent software in ANSYS 12

## 1. What is an orifice and how does it affect pressure and temperature?

An orifice is a small opening or hole in a surface. In fluid mechanics, it is commonly used to measure flow rate. As fluid flows through an orifice, there is a pressure drop due to the restriction of the flow area. This pressure drop also causes a decrease in temperature due to the Joule-Thomson effect.

## 2. How do pressure and temperature change as fluid flows through an orifice?

As fluid flows through an orifice, there is a significant pressure drop due to the restriction of the flow area. This decrease in pressure also causes a decrease in temperature due to the Joule-Thomson effect. The amount of pressure and temperature drop depends on the properties of the fluid, the size and shape of the orifice, and the flow rate.

## 3. What is the relationship between pressure drop and temperature drop in an orifice?

The pressure drop and temperature drop in an orifice are directly proportional. This means that as the pressure drop increases, the temperature drop also increases. This relationship is due to the Joule-Thomson effect, which describes the change in temperature of a gas as it expands into a lower pressure region.

## 4. How can the pressure and temperature drop in an orifice be calculated?

The pressure and temperature drop in an orifice can be calculated using the Bernoulli's equation, which describes the conservation of energy in a fluid flow. This equation takes into account the fluid's properties, the size and shape of the orifice, and the flow rate to calculate the pressure and temperature drop.

## 5. What factors can affect the pressure and temperature drop through an orifice?

The pressure and temperature drop through an orifice can be affected by several factors, including the properties of the fluid (such as density and viscosity), the size and shape of the orifice, the flow rate, and the temperature and pressure of the fluid before and after the orifice. Other factors such as the presence of impurities or changes in the orifice's surface roughness can also affect the pressure and temperature drop.