Interactive Self-Study Module: Reversible and Irreversible Expansion/Compression Processes 
Department of Chemical and Biological Engineering, University of Colorado Boulder 

This module uses screencasts and interactive simulations to explain the differences between reversible and irreversible expansion and compression processes. Example problems are provided to allow the user to test themselves. We suggest using the learning resources in the following order: 

  1. Attempt to answer the multiple choice ConcepTests before watching the screencasts or working with the simulations.
  2. Watch the screencasts that describe expansion and compression processes and answer the questions within the screencasts.
  3. Use the interactive simulation to further understand reversible and irreversible processes.
  4. Use the quiz interactive simulation to test your understanding by identifying isothermal and adiabatic curves on P-T and P-V diagrams.
  5. Try to solve the two example problems before watching the solutions in the screencasts.
  6. Answer the ConcepTests.

Expansion and compression processes are used in many engineering applications.

This module is intended for a Thermodynamics course.

Before studying this module, you should:

After studying this module, you should be able to:
  1. Irreversible expansion does less work than a reversible expansion process that starts at the same conditions and ends at the same pressure. 
  2. Irreversible compression requires more work than a reversible compression for a process that has the same initial conditions and the same final pressure.
  3. The entropy always increases for an irreversible adiabatic process.
  4. The final temperature is higher for an irreversible adiabatic process than for a reversible adiabatic process that starts at the same initial condition and ends at the same pressure.
  5. Sketch reversible and irreversible processes on T-S, H-S, P-H, and P-T diagrams for the same initial conditions.