Compression and Expansion of Gases

Calculate pressure and density relationships for isothermal, isentropic, and polytropic compression/expansion processes of gases

Process Type	Initial Pressure (Pa)	Initial Volume (m³)	Initial Density (kg/m³)	Final Volume (m³)	Final Pressure (Pa)	Final Density (kg/m³)	Parameter k or n
Isothermal	101325	1	1.2	0.5	202650	2.4	—
Isentropic	101325	1	1.2	0.5	323560	3.84	1.4
Polytropic	101325	1	1.2	0.5	262725	3.12	1.2

Calculator

Process Type

Initial Pressure (p₁) (Pa)

Initial Volume (V₁) (m³)

Initial Density (ρ₁) (kg/m³)

Final Volume (V₂) (m³)

k (cp/cv) or n (polytropic index) (—)

Final Pressure (p₂)-- Pa

Final Density (ρ₂)-- kg/m³

Pressure Ratio (p₂/p₁)-- —

Density Ratio (ρ₂/ρ₁)-- —