Throttling Process

Throttling Process Explained With Real Life Situation's

1. Throttling   is the process in which a fluid passing through a restriction loses pressure.  Throttling Process

2. A B Compare A & B A is ILLUSTATION to show throttling which happens in different mechanisms such as B.

3. Now imagine their are students in a class room and as the bell rungs they started moving out. Now if the door is opened partially then their will be clusters form by the students. Similarly in flow of fluid their is restriction to flow. now as students form clusters they pushing other students and in the same way fluid particles start rubbing with other molecules and as a result friction is their and as we all know  friction  is one of the biggest reason for any process to make it  irreversible. Hence it is clear that Throttling is irreversible. Throttling Is Irreversible Explanation W ith R eal-Life Example

4. 1 . Flow through a partially opened valve as in  IC engines 2. Flow through a very small opening e.g.  orifice. 3. Flow through a  porous plug . EXAMPLES OF THROTTLING PROCESS

5. Characteristics of Throttling No Work Transfer No Heat Transfer Irreversible Process 4. Isenthalpic Process

6. Explanation: As we know their is work transfer in turbines due to very large pressure difference. but in the case of throttling their is very low pressure differences so the work we get is very small and this work is lost in overcoming friction. so here we generally neglect the work transfer. 1. No Work Transfer

7. Explanation:  Lets see it with a example... imagine you open the freeze and took out your water bottle and just within the fraction of seconds you put back that bottle, now what is the temperature difference between the two states of the water bottle, it is approx. zero. It means heat transfer needs some time , now what happened in throttling is that device length is very small and the fluid is always pushed ahead due to the bulk coming and due this their is not much time for the heat transfer. As we are considering the steady flow and bulk is not accumulated in the device so heat transfer is also neglected. 2. No Heat Transfer

8. 3. Irreversible Process

9. 4. Isenthalpic Process Explanation: The word ISENTHALPIC means same Enthalpy. Look we apply steady flow energy equation: now neglecting potential energy changes and heat transfer(q) and work transfer (w) are zero as the characteristics of throttling.. Equation becomes: now what we generally seen that practically velocities values (c1 and c2 ) are very very small as compared to enthalpies values so c1 and c2 can be neglected and finally Hence the process is Isenthalpic.

10. Thank You