1. What is Heat Engine Efficiency?

Heat engine efficiency (η) measures how effectively a heat engine converts thermal energy into mechanical work. It represents the ratio of work output to heat input, following the second law of thermodynamics.

2. How Does the Calculator Work?

The calculator uses the Carnot efficiency formula:

Where:

• \( T_c \) — Cold reservoir temperature (K)
• \( T_h \) — Hot reservoir temperature (K)

Explanation: This formula gives the maximum possible efficiency for a heat engine operating between two temperature reservoirs, as established by Sadi Carnot.

3. Importance of Efficiency Calculation

Details: Calculating heat engine efficiency is crucial for designing thermal systems, optimizing energy conversion processes, and understanding the theoretical limits of thermodynamic cycles.

4. Using the Calculator

Tips: Enter both temperatures in Kelvin (K). The hot reservoir temperature must be greater than the cold reservoir temperature. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: Why must temperatures be in Kelvin?
A: The efficiency formula requires absolute temperature values, and Kelvin is the absolute temperature scale where 0 represents absolute zero.

Q2: What is the maximum possible efficiency?
A: The maximum efficiency is always less than 100% (η < 1) according to the second law of thermodynamics.

Q3: Can real engines achieve Carnot efficiency?
A: No, real engines always have lower efficiency due to various irreversibilities and practical limitations.

Q4: What are typical efficiency values?
A: Real heat engines typically achieve 20-40% efficiency, while theoretical Carnot efficiency can be much higher depending on temperature difference.

Q5: Does this apply to all heat engines?
A: This formula gives the maximum theoretical efficiency for any heat engine operating between two temperature reservoirs.