# Temperature change after flow through an oriface

• gbq57
In summary, an orifice is created between two chambers of different pressure, and the pressure and temperature changes of the gas in each chamber as a result of the flow. There is no work being done in the system, and the temperature is assumed to be constant.

#### gbq57

I'm interested in modelling the effect of a chamber of ideal gas at a high pressure passing through subsequent chambers of lower pressure gas - each subsequent chamber joined to the previous via a thin plate oriface.

I'm looking at at an iterative solution (i don't do integrals) and i am happy that i can calculate the instantaneous flow of gas through an orifice between chambers - whether chocked or not.

I can not find how to calculate the temperature change of the gas in each of the chambers either side of the orifice as a result of the flow (assuming no 'velocity' of gas remains in any of the chambers).

There is no work being done in the system and I know during a free adiabatic expansion the temperature is constant but this scenario is different - I assume temperature/internal energy will drop in the high pressure side and increase in the low pressure side as the gas passes through the orifice - but by how much - can someone point me to a formula or another way of looking at the problem?

Ok - let's put some real figures on this to get the ball rolling...

Assume the gas concerned is air - 29 mol/g, k=1.4

Chamber A has 5g of air (0.1724 mols) in 1 litre at 1000 Kelvin.
P=nRT/V
pressure = 1.433Mpa
density = 5g/l (5kg/m3)

Chamber B has 2.4g of air (0.0827 mols) in 2 litres at 300 Kelvin
pressure = 0.103Mpa
density = 1.2 g/l

The chambers are connected by a 10mm diameter orifice with a discharge Coefficient (C) of 0.76

If the orifice was opened for approx 4.7 milliseconds then closed then I calculate around 0.5 grams of gas would rush under choked conditions to chamber B. But what would the pressure/temperature be in both of the chambers assuming no loss of energy outside the system?

any help, informed guesses, discussion is welcome!

any one - am I asking something difficult/unknown?

## 1. What causes temperature change after flow through an oriface?

The change in temperature after flow through an oriface is caused by the exchange of heat between the fluid and the surroundings during the flow process.

## 2. How does the temperature change after flow through an oriface?

The temperature change after flow through an oriface depends on various factors such as the type of fluid, the flow rate, the size of the oriface, and the temperature of the surroundings.

## 3. Is there a relationship between the flow rate and the temperature change after flow through an oriface?

Yes, there is a direct relationship between the flow rate and the temperature change after flow through an oriface. As the flow rate increases, the temperature change also increases due to the faster exchange of heat between the fluid and the surroundings.

## 4. Can the temperature change after flow through an oriface be controlled?

Yes, the temperature change after flow through an oriface can be controlled by adjusting the flow rate, the size of the oriface, and the temperature of the surroundings. These factors can be manipulated to achieve the desired temperature change.

## 5. What are the applications of studying temperature change after flow through an oriface?

The study of temperature change after flow through an oriface has various applications in industries such as chemical, petroleum, and environmental engineering. It is also important in understanding the behavior of fluids and their effects on the environment.