Energy & Environment · Heat and efficiency / Principles and inquiry
Heat engine and Carnot efficiency experiment guide
Vary hot and cold reservoir temperatures to compare work, waste heat and efficiency limits.
How does it work?
Carnot efficiency calculated in kelvin is the upper limit. Some input heat flows to the cold reservoir.
Key relationship
ηCarnot = 1 − Tc/Th · W = Qin ηCarnot f · Qout = Qin − W
Try this investigation
- Vary hot and cold reservoir temperatures to compare work, waste heat and efficiency limits.
- Run and record each of the three reference settings.
- Change one variable in each comparison and compare its energy results with the baseline.
Interpreting your results
Which temperature unit belongs in the Carnot formula?
K · Carnot efficiency calculated in kelvin is the upper limit. Some input heat flows to the cold reservoir.
Assumptions and limitations
This simplified cyclic engine uses two reservoirs. Quality is a fraction of Carnot efficiency, not an engineering design rating. Combustion and friction are not resolved. Do not reproduce this with flames, hot or pressurized equipment.