Carnot Cycle
Introduction
- Isothermal expansion: Heat is transferred from the hot reservoir to the gas.
- Isentropic (reversible adiabatic) expansion: without transfer of heat to or from a system, so that Q = 0, is called adiabatic, and such a system is said to be adiabatically isolated. Eg. the compression of a gas within a cylinder of an engine is assumed to be rapid that little of the system's energy is transferred out as heat to the surroundings.
- Isothermal compression
- Isentropic compression
Ideal Gas

, or more genrally polytropic process: Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle pV^\gamma = C} , where is different processes depending on the value of the n:
- n = 0: isobaric
- n = ∞: isochoric
- n = 1: isothermal
- n = γ: isentropic
Adiabatic index Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \gamma = c_p/c_v} is for the air 7/5. For the ideal gas we have Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle p^{1-\gamma} T^\gamma = C} and Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle TV^{\gamma-1} = C} .
- (n=1) Isothermal compression: T is constant, thus we have Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle p =C/V } .
- (n=γ) Isentropic Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle p=C/V^\gamma}