What quantity did you change?
Labs / Physics
Heat Engine Cycle
Press Run to push the gas around a four-stage cycle: squeeze it cold, heat it up, let it expand hot, then cool it back down. The loop traced on the pressure–volume chart encloses an area, and that area is exactly the net work the engine delivers each cycle. Nudge the reservoir temperatures and the compression ratio to see how much work you can wring out.
Labs / Physics / Heat Engine Cycle
Heat Engine Cycle
Press Run to push the gas around a four-stage cycle: squeeze it cold, heat it up, let it expand hot, then cool it back down. The loop traced on the pressure–volume chart encloses an area, and that area is exactly the net work the engine delivers each cycle. Nudge the reservoir temperatures and the compression ratio to see how much work you can wring out.
Why it matters
Why explore this?
Physics explains how changes in forces, energy, motion, and matter produce results we can measure. This model lets you test one part of that relationship at a time.
Explore
Try the model
Stage Isothermal compressionT 300 KW 3.00 kJη 31% / Carnot 46%
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- Widen the gap between the hot and cold temperatures. Does the loop grow, and does the efficiency climb toward the Carnot limit?
- Slide the cold reservoir up until it nearly meets the hot one. What happens to the work when there's hardly any temperature difference?
- Crank the compression ratio to 8×. How does squeezing the gas harder change the shape and area of the PV loop?
- Why does the real efficiency always sit below the Carnot number, no matter how you set the sliders?
- Use Step to freeze on each corner. Which two stages take heat in from the hot source, and which two dump heat to the cold sink?
Explain
Make sense of what happened
Name the quantity you changed, the quantity that responded, and the physical rule connecting them. Use a readout or visible change as evidence.
Check
Before you leave
What measurable result changed?
Which physical idea connects them?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.