CANKAYA UNIVERSITY
FACULTY OF ENGINEERING AND ARCHITECTURE
MECHANICAL ENGINEERING DEPARTMENT
ME 211 THERMODYNAMICS I
FALL 2015
HW # 3 SOLUTION
1) Water vapor initially at 10 bar and 400°C is contained within a piston–cylinder assembly.
The water is cooled at constant volume until its temperature is 150°C. The water is then
condensed isothermally to saturated liquid. For the water as the system, evaluate the
work, in kJ/kg.
Solution
2)
3) At 300°C and 100 kPa air has a volume of 0.8 m3. In a constant-volume process the
pressure of air changes to 50 kPa. Determine the heat transferred to the air and the final
temperature of air. Take the value of specific heat capacity at constant volume for air
equal to 0.718 kJ/kg.K ?
4) Determine the volume, in m3, occupied by 40 kg of nitrogen (N2) at 17 MPa, 180 K. Use
compressibility chart.
5) A cylinder fitted with a piston has a volume of 0.1 m3 and contains 0.5 kg of steam at 0.4
MPa, Heat is transferred to steam until temperature is 300 0C ,while pressure remains
constant.Determine the heat transfer and the work for this process
Solution
6) A cylinder fitted with a piston has an initial volume of 0.1 m3 and contains nitrogen at
150 kPa, 25 0C. The piston is moved, compressing the nitrogen until the pressure is 1
MPa and the temperature is 150 0C. During this compression process heat is transferred
from the nitrogen, and the work done on the nitrogen is 20 kJ. Determine the amount of
this heat transfer.
7) A piston/cylinder arrangement with a linear spring similar to figure given below contains
R-134a at 15 0C, x=0.4 and a volume of 0.02 m3. It is heated to 60 0C, at which point the
specific volume is 0.03002 m3/kg. Find the final pressure, the work, and the heat transfer
in the process.