What does the polytropic index represent?

What does the polytropic index represent?

The value of n is different in different thermodynamic processes. Some examples are given below. The polytropic index is a measure of the work done by the system. Word of caution: Many gas compression and expansion processes may be approximated by a polytropic process.

What does polytropic process becomes if value of index n 1?

When n=1 then pv=k i.e constant . It means Isothermal process.

What is the meaning of polytropic process?

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.

What are Polytropes used for?

Polytropes are self-gravitating gaseous spheres that were, and still are, very useful as crude approximation to more realistic stellar models. Properties of polytropes are thoroughly described in a classical, and very old, textbook: An Introduction to the Study of Stellar Structure by S.

How is polytropic process related to isobaric process?

All the standard processes like isobaric, isochoric, adiabatic, and isothermal processes belong to the category of polytropic process. Polytropic process equation can be used to describe various compression and expansion processes which include heat transfer. It corresponds to isobaric i.e constant pressure process.

What does N 1 value indicate?

The value of n = 1 in the polytropic process indicates it to be. Reversible process. Adiabatic process.

What value n is equal to 1 indicates in polytropic process PV is equal to constant?

If n = 1 ⇒ Process is Isothermal or Constant temperature.

What is adiabatic and polytropic process?

Adiabatic Versus Polytropic Process An adiabatic process is a reversible constant entropy process for an ideal gas without heat transfer, following the relationship. Pvk = constant. A polytropic process is a reversible process for an ideal gas with heat transfer, and variable entropy, following the relationship.

What is the polytropic index for isothermal process?

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.

Are polytropic processes isothermal?

Isothermal process are a subset of the polytropic. Polytropic encompass all other common processes and more. standard notation implying C is a constant, P the pressure and V the volume.

What is the difference between an isentropic and a polytropic process?

Isentropic process is one in which the entropy remains constant throughout. Polytropic process is one which obeys the law given below throughout the process.

Why is the specific heat of polytropic process negative?

This expression shows that specific heat of polytropic process is negative only for n values in the interval ( 1, γ). It is negative because, to execute such a process with n ϵ ( 1, γ), more work should be done by the system than the heat added or more work should be done on the system than the heat removed.

What is P in polytropic process equation?

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.

What is the relation between polytropic coefficient and ratio of energy transfers?

Equivalence between the polytropic coefficient and the ratio of energy transfers. For an ideal gas in a closed system undergoing a slow process with negligible changes in kinetic and potential energy the process is polytropic, such that where C is a constant, , , and with the polytropic coefficient .

How do you calculate the heat of compression from the polytropic index?

Determining the polytropic index ( n) is usually done experimentally. If you have a value for n, then you can determine the heat of compression by Eq. (8.4).