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Thermal Efficiency Formula:
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Thermal efficiency of an internal combustion engine is defined as the ratio of work done per cycle to the actual heat input per cycle in the engine. It represents how effectively the engine converts heat energy from fuel combustion into useful mechanical work.
The calculator uses the thermal efficiency formula:
Where:
Explanation: The formula calculates the efficiency by dividing the useful work output by the total heat energy input from fuel combustion.
Details: Calculating thermal efficiency is crucial for evaluating engine performance, optimizing fuel consumption, comparing different engine designs, and identifying areas for improvement in energy conversion processes.
Tips: Enter work done per cycle in Joules and heat added by combustion per cycle in Joules per kilogram. Both values must be positive numbers greater than zero.
Q1: What is a typical thermal efficiency range for IC engines?
A: Most modern internal combustion engines have thermal efficiencies between 20-40%, with diesel engines typically being more efficient than gasoline engines.
Q2: Why can't thermal efficiency reach 100%?
A: Due to the second law of thermodynamics, heat engines cannot convert all heat energy into work. Some energy is always lost as waste heat through exhaust and cooling systems.
Q3: How does thermal efficiency relate to fuel economy?
A: Higher thermal efficiency means more work is extracted from the same amount of fuel, resulting in better fuel economy and lower emissions.
Q4: What factors affect thermal efficiency?
A: Compression ratio, combustion efficiency, friction losses, heat transfer losses, and mechanical efficiency all impact the overall thermal efficiency.
Q5: How can thermal efficiency be improved?
A: Through technologies like turbocharging, direct injection, variable valve timing, reduced friction components, and improved combustion chamber design.