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UMLAZI KWAZULU-NATAL
P.O. Box 1263 Jacobs 4026 Durban Tell: 031 907 7111 Fax: 031 907 2892
THERMODYNAMICS APPLIED III: TUTORIAL #2
THERMODYNAMICS PROCESSES (APPLICATIONS)
1. Determine work done by fluid in the thermodynamic cycle comprising of following processes:
a) Unit mass of fluid at 20 atm and 0.04 m3 is expanded by the law PV1.5 = constant, till volume
gets doubled.
b) Fluid is cooled isobarically to its original volume.
c) Heat is added to fluid till its pressure reaches to its original pressure, isochorically.
2. Determine the heat transfer in emptying of a rigid tank of 1 m3 volume containing air at 3 bar and
27°C initially. Air is allowed to escape slowly by opening a valve until the pressure in tank drops
to 1 bar pressure. Consider escape of air in tank to follow polytropic process with index n = 1.2
3. A fluid at a pressure of 3 bar, and with specific volume of 0.18 m3/kg, contained in a cylinder behind
a piston expands reversibly to a pressure of 0.6 bar according to a law, p = C/v2 where C is a
constant. Calculate the work done by the fluid on the piston.
4. A cylinder contains 1 kg of a certain fluid at an initial pressure of 20 bar. The fluid is allowed to
expand reversibly behind a piston according to a law pV2 = constant until the volume is doubled.
The fluid is then cooled reversibly at constant pressure until the piston regains its original position;
heat is then supplied reversibly with the piston firmly locked in position until the pressure rises to
the original value of 20 bar. Calculate the net work done by the fluid, for an initial volume of 0.05
m3.
5. To a closed system 150 kJ of work is supplied. If the initial volume is 0.6 m3 and pressure of the
system changes as p = 8 – 4V, where p is in bar and V is in m3, determine the final volume and
pressure of the system.
UMLAZI KWAZULU-NATAL
P.O. Box 1263 Jacobs 4026 Durban Tell: 031 907 7111 Fax: 031 907 2892
THERMODYNAMICS APPLIED III: TUTORIAL #2
THERMODYNAMICS PROCESSES (APPLICATIONS)
1. Determine work done by fluid in the thermodynamic cycle comprising of following processes:
a) Unit mass of fluid at 20 atm and 0.04 m3 is expanded by the law PV1.5 = constant, till volume
gets doubled.
b) Fluid is cooled isobarically to its original volume.
c) Heat is added to fluid till its pressure reaches to its original pressure, isochorically.
2. Determine the heat transfer in emptying of a rigid tank of 1 m3 volume containing air at 3 bar and
27°C initially. Air is allowed to escape slowly by opening a valve until the pressure in tank drops
to 1 bar pressure. Consider escape of air in tank to follow polytropic process with index n = 1.2
3. A fluid at a pressure of 3 bar, and with specific volume of 0.18 m3/kg, contained in a cylinder behind
a piston expands reversibly to a pressure of 0.6 bar according to a law, p = C/v2 where C is a
constant. Calculate the work done by the fluid on the piston.
4. A cylinder contains 1 kg of a certain fluid at an initial pressure of 20 bar. The fluid is allowed to
expand reversibly behind a piston according to a law pV2 = constant until the volume is doubled.
The fluid is then cooled reversibly at constant pressure until the piston regains its original position;
heat is then supplied reversibly with the piston firmly locked in position until the pressure rises to
the original value of 20 bar. Calculate the net work done by the fluid, for an initial volume of 0.05
m3.
5. To a closed system 150 kJ of work is supplied. If the initial volume is 0.6 m3 and pressure of the
system changes as p = 8 – 4V, where p is in bar and V is in m3, determine the final volume and
pressure of the system.
