# What is index expansion?

## What is index expansion?

A polytropic process is a thermodynamic process that obeys the relation: where p is the pressure, V is volume, n is the polytropic index, and C is a constant. The polytropic process equation can describe multiple expansion and compression processes which include heat transfer.

## How do you calculate polytropic index?

1 Polytropic Process. where v = 1 / ρ is the specific volume, n is the polytropic index, and C is a constant. The condition of represents an isobaric process, represents an isothermal process, n = γ = c p / c v represents an isentropic process, and represents an isochoric process.

## What is compression and expansion?

Compression is a process under which volume of the system is gradually reduced, pressure and temperature increases where heat transfer may or may not be possible. While in expansion process volume is gradually decrease with the decrease in pressure and temperature and heat transfer may or may not be possible.