EngiRef / Thermodynamics Engineering Formula

Otto Cycle Efficiency

Otto Cycle Efficiency: Thermal efficiency of ideal Otto cycle. A Cycles formula in thermodynamics engineering. Variables η, r and γ, each with SI and imperial…

Cycles

Specification

Name
Otto Cycle Efficiency
Discipline
thermodynamics
Category
Cycles
LaTeX
\eta = 1 - \frac{1}{r^{\gamma-1}}
Description
Thermal efficiency of ideal Otto cycle
Conditions
Ideal spark-ignition engine cycle
Can solve for
η, r
Tags
otto, cycle, efficiency, compression, engine

Variables

Variables for Otto Cycle Efficiency
SymbolNameUnitSi Unit
ηEfficiency - -
rCompression Ratio - -
γSpecific Heat Ratio - -

Common questions

What is the Otto Cycle Efficiency formula?
Thermal efficiency of ideal Otto cycle. It sits under Cycles, Thermo engineering in the EngiRef reference.
What do the symbols in the Otto Cycle Efficiency formula mean?
In Otto Cycle Efficiency, η is efficiency; r is compression ratio; γ is specific heat ratio.
When does the Otto Cycle Efficiency formula apply?
Otto Cycle Efficiency holds under this condition: Ideal spark-ignition engine cycle.