2. Modes of Work Transfer P M V Subbarao Professor Mechanical Engineering Department I I T Delhi Development of Power for Different Needs!!!

3. Negative Work When a system does positive work, its surroundings do an equal quantity of negative work. Conversely, when surroundings do positive work, the system does and equal quantity of negative work.

4. Types of Work Transfers Moving Boundary work (displacement work) Electrical work Shaft work Flowing fluid work

5. Moving Boundary work (displacement work) Boundary work occurs when a change in the system causes a force to act on the boundary and make it move.

6. Simple Processes for Displacement Work : Control Mass

7. Control Mass : Constant Volume & Pressure Processes

8. Isothermal Process by A Control Mass

9. Isothermal Process of Real Gases in a Control Mass Van der Waals EOS

11. Displacement Work done by Superheated Steam During An Isothermal Process

12. Generalized Process in A Control Mass p = p 0 + k (V-V 0 ) p 2 = p 0 2 + k (V-V 0 ) 2 Polytropic Nature of Fluid Process: pV n = Constant –n: Polytropic constant. –n=0 : Constant Pressure Process. –n= : Constant Volume Process.

13. The Polytropic Process by A Control Mass One in which the pressure-volume relation is given as PV n =constant n may have any value from minus to plus infinity. Work transfer during a polytropic process.

14. For a vapour under going a polytropic process.