Explain the operation of thermodynamic systems and their

Question

Q-1

a) The work done by the expansion of unit mass of a fluid from state 1 to 2 during a polytropic process:

Figure 1: Schematic P-V diagram for polytropic process

b) The relationship between the index ‘n' and heat transfer during a polytropic process

c) A piston-cylinder device initially contains 0.6 m³ of air at 120 kPa and 850C and is compressed isothermally. If the temperature inside the cylinder remains constant and the air is finally compressed to 0.3m3. Determine thework done during this process.

Q-2: Explain the operation of thermodynamic systems and their properties
a) List and explain briefly four thermodynamic properties.

Q-3: With respect to the thermodynamic analysis, explain the following terms:
(i) Isothermal process
(ii) Isochoric process
(iii) Reversible process
(iv)Adiabatic process

Q-4: State and explain the first law of thermodynamics. Discuss and evaluate with suitable examples and diagrams its application to one closed system and one open system.

Q-5: Steam is supplied to a turbine at a pressure of 200 bar and a temperature of 600°C through a pipe 0.4 m in diameter. The steam is exhausted at 0.2bar with a dryness fraction of 0.80 through a duct of 6 m² cross-sectional area. When supplied with steam at the rate of 25 kg/s, the turbine develops 16.5 MW of power output. Neglecting potential energy changes, calculate the rate of heat transfer from the turbine. Explain clearly how you obtained from the steam table the values used for your calculations.

Q-6: Starting from the basic thermodynamic concepts, show that

(a) the relationship between R (gas constant) and the specific heat capacities can be expressed as: C_p-C_v = R.

(b) For an adiabatic process, the relationship between the specific heat capacities can be expressed as: C_p/C_v = γ