![]() Where the subscripts 1 and 2 refer to the initial and final states of the gas.Įngineering thermodynamics makes extensive use of the concept of polytropic processes in investigating the operating cycles of heat engines. The work A done by an ideal gas against the ambient pressure is determined from the formula Special cases of the equation of a polytropic process for an ideal gas are the equations for an isentropic curve, where C = 0 and n = C p/cv (this ratio of specific heats is designated γ) an isobar, where C- C p and n = 0 an isochor, where C= Cv and n = ∞ and an isotherm, where C= ∞ and n = 1. By using the equation of state for an ideal gas, the equation of a polytropic curve can be written in a different form: pT n/(1-n)= const or VT 1(1-n) = const, here T is the absolute temperature. change Category: Chemical Engineering Mcqs, Published by: T-Code Scripts. This process is defined by the equation pV n= const, where p is the pressure of the gas, V is the volume of the gas, and n = (C- C P)/(C- Cv) is the polytropic exponent ( Cp and Cv are the specific heats of the gas at constant pressure and constant volume, respectively). MCQs: Generation of heat by friction is an example of a/an. The curve representing a polytropic process on a thermodynamic diagram is called a polytropic curve.Ī simple example of a reversible polytropic process is the polytropic change of an ideal gas. What is polytropic process in physics 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. Calculate (a) the final pressure and temperature of the air, (b) the work done and (c) the energy transferred as heat per mole of the air. In a reversible isothermal process, the temperature remains a constant. An example of a polytropic process is the expansion of the combustion gasses in the cylinder of a water-cooled reciprocating engine. ![]() A change in the state of a physical system where the system’s specific heat C remains constant. expressions like the expression for work done, the expression for heat transfer. ![]()
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