Polytropic Process Definition

November 26, 2023 Post a Comment

Polytropic process definition

The term "polytropic" was originally coined to describe any reversible process on any open or closed system of gas or vapor which involves both heat and work transfer, such that a specified combination of properties were maintained constant throughout the process.

What is polytropic process example?

An example of a polytropic process is the expansion of the combustion gasses in the cylinder of a water-cooled reciprocating engine.

What is the difference between adiabatic and polytropic process?

Hence, the key difference between adiabatic and polytropic processes is that in adiabatic processes no heat transfer occurs whereas in polytropic processes heat transfer occurs. Moreover, the equation dQ=0 is true for the adiabatic process while the equation PVn=constant is true for the polytropic process.

What is polytropic process for ideal gas?

A polytropic process for an ideal gas is represented by equation = PV^n constant. If gamma is ratio of specific heats (Cp/Cv) . then value of n for which molar heat capacity of the process is negative, is given as.

What is difference between isentropic and polytropic process?

An isentropic process is a thermodynamic process in which both adiabatic and reversible natures can be observed. A polytropic process is a reversible process on any open or closed system of gas or vapor involving both heat and work transfer.

Is a polytropic process 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.

Are all adiabatic process polytropic?

Polytropic process is a general process for which PV^n=constant. But adiabatic process is a particular case of polytropic process for which n=gamma, i.e., PV^gamma=constant. In adiabatic process, no heat transfer takes place whereas for polytropic process heat transfer may or may not take place.

What is the difference between polytropic and isentropic efficiency?

The key difference between the polytropic and the isentropic efficiency is that the reference compression process in the definition of the reversible work is taken as a reversible compression path from the inlet state 1 to outlet state 2.

Why polytropic efficiency is higher than adiabatic efficiency?

From this relationship, it is obvious that polytropic efficiency is the limiting value of the isentropic efficiency as the pressure increase approaches zero, and the value of the polytropic efficiency is higher than the corresponding adiabatic efficiency.

What happens to temperature in a polytropic process?

Ans: In a polytropic process where PVn =constant, the temperature remains constant only when the polytropic index n = 1. For n = 1: PV = C: Under the Assumption of Ideal Gas Law, The PV = C represents the Constant Temperature or Isothermal Process.

Is Isochoric process polytropic?

Since the volume remains constant, the heat transfer into or out of the system does not the p∆V work but only changes the system's internal energy (the temperature). The case n ➝ ∞ corresponds to an isochoric (constant-volume) process for an ideal gas and a polytropic process.

Can polytropic process use specific volume?

1 Polytropic Process. where 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, represents an isentropic process, and represents an isochoric process. with E being the internal energy per unit initial volume.

Why do we use polytropic efficiency?

Polytropic work is helpful because it preserves the discharge temperature of the overall compressor and the inlet and exit gas conditions are maintained.

Is isentropic and adiabatic the same?

In thermodynamics, an isentropic process is an idealized thermodynamic process that is both adiabatic and reversible. The work transfers of the system are frictionless, and there is no net transfer of heat or matter.

What is polytropic constant?

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 describes expansion and compression processes which include heat transfer.

Is isobaric a polytropic process?

The isobaric, isothermal, isentropic and isochoric processes are therefore only to be regarded as special cases of a generally polytropic process!

What is non polytropic process?

But there are processes where pressure and volume of a gas varies with correlating factor less than one (n may be less than one). All these processes are considered as polytropic processes. All the processes other than this are called non-polytropic processes.

Which of the following is true for a polytropic process?

Which of the following is true for a polytropic process? Explanation: These are the properties of an adiabatic process. Explanation: It comes from the p1*(v1^n) = p2*(v2^n).

Is every process polytropic?

No, all thermodynamic processes are not polytropic.

What is meant by adiabatic process?

An adiabatic process is defined as a process in which no heat transfer takes place. This does not mean that the temperature is constant, but rather that no heat is transferred into or out from the system.