1. What is Thermal Efficiency?

Definition: Thermal efficiency measures how well a heat engine converts heat energy into useful work.

Purpose: It helps engineers and scientists evaluate the performance of engines, power plants, and other thermal systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \eta \) — Thermal efficiency (%)
• \( W_{net} \) — Net work output (Joules, J)
• \( Q_{in} \) — Heat input (Joules, J)

Explanation: The ratio of net work output to heat input is multiplied by 100 to express efficiency as a percentage.

3. Importance of Thermal Efficiency

Details: Higher efficiency means more useful work is obtained from the same amount of heat input, leading to better fuel economy and reduced environmental impact.

4. Using the Calculator

Tips: Enter the net work output and heat input in joules. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a good thermal efficiency value?
A: Typical values range from 20-40% for automobile engines, 30-50% for power plants, and up to 60% for combined cycle plants.

Q2: Can efficiency exceed 100%?
A: No, that would violate the first law of thermodynamics (energy conservation).

Q3: What are common units for these measurements?
A: While joules are standard, BTU or calories can be used if both inputs are in the same units.

Q4: How does this relate to Carnot efficiency?
A: Carnot efficiency is the theoretical maximum possible efficiency between two temperature reservoirs.

Q5: What factors affect thermal efficiency?
A: Temperature differences, friction, heat losses, and system design all impact efficiency.