Thermodynamic Properties Phase Diagrams: Interactive Simulations
These simulations will run in your browser. Try to predict the behavior when a parameter changes before using a slider to change that parameter. Screencasts below explain how to use most of these simulations.
Simulation: Pressure-Enthalpy Diagram for Water
Try to answer these questions before determining the answer with the simulation. We suggest that you write down the reasons for your answers.
- At low pressures and high enthalpies, how does enthalpy change with pressure? Why?
- At low enthalpies and relatively high pressures, how does enthalpy change with pressure? Why?
- At a low, constant quality, how does the enthalpy change as temperature increases?
Simulation: Temperature-Entropy Diagram for Water
Try to answer this question before determining the answer with the simulation. We suggest that you write down the reasons for your answer.
- In the vapor region on a temperature-entropy diagram, as the temperature increases at constant entropy, what changes and how?
Simulation: Pressure-Volume Diagram for Water
This simulation helps you learn how to read pressure-volume diagrams. This diagram contains constant enthalpy, entropy, temperature, and quality lines in every phase (gas, liquid, solid). You can toggle each property on or off to make the diagram easier to read. It also helps you understand water behavior in the 2-phase region, because the diagram contains a phase envelope.
Try to answer this question before determining the answer with the simulation. We suggest that you write down the reasons for your answer.
- A fixed-volume container has 9 kg of liquid water and 1 kg of water vapor at 0.10-MPa pressure. The pressure and temperature increase. Does the entropy increase, decrease, or not change?
This demonstration shows a enthalpy-entropy (H-S) diagram for water. Use the checkboxes to display lines of constant pressure (purple), temperature (green) or vapor quality (mass% vapor, blue). Check “phase envelope” to show saturated liquid (magenta) and saturated vapor (orange) curves and the critical point (black dot).
Try to answer these questions before determining the answer with the simulation. We suggest that you write down the reasons for your answers.
- Locate the critical point on the phase envelope on the enthalpy-entropy diagram.
- In the phase envelope, why are the constant pressure lines parallel to the constant temperature lines?