King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 1 (Term 072)
Monday 17-3-2008
15 Minutes
Student Name
ID #
A
A gasoline line is connected to a pressure gage through a double-U manometer. For a
given reading of the pressure gage,
1. Determine the gage pressure of the gasoline line.
2. Determine the absolute pressure of the gasoline line.
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 1 (Term 072)
Monday 17-3-2008
15 Minutes
Student Name
ID #
B
A gasoline line is connected to a pressure gage through a double-U manometer. The
gage pressure of the gasoline line is 165 kPa.
1. Determine the reading of the pressure gage.
2. Determine the absolute value of the pressure at A
A
165 kPa
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 1 (Term 072)
Monday 17-3-2008
15 Minutes
Student Name
ID #
A
A water pipe is connected to a double U-tube
manometer as shown in figure at a location
where local atmospheric pressure is 98 kPa.
Determine the absolute pressure at the
center of the pipe.
Oil SG = 0.8
Mercury SG = 13.6
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 2 (Term 072)
Saturday 22-3-2008
35 Minutes
Student Name
ID #
A
Fill the following table
Substance
H2O
H2O
H2O
R134a
R134a
T, oC
250
105
340
Substance
H2O
H2O
H2O
R134a
R134a
P, kPa
1800
v, m3/kg
u kJ/kg
x
Phase description
1
0.025
50
8200
360
2000
T, oC
250
105
340
5.82
50
P, kPa
1800
120.8
8200
360
2000
v, m3/kg
0.125
1.42
0.02806
0.025
0.0009013
* quality not defined
2645
u kJ/kg
2685
2512
2715
134.6
121.4
X
*
1
*
0.4322
*
Phase description
Superheated vapor
Saturated vapor
Superheated vapor
Saturated mixture
Compressed liquid
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 2 (Term 072)
Saturday 22-3-2008
35 Minutes
Student Name
ID #
B
Fill the following table
Substance
R134a
H2O
R134a
H2O
H2O
T, oC
340
50
105
250
P, kPa
360
8200
2000
v, m3/kg
0.025
u kJ/kg
x
2645
1
1800
Phase description
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 2 (Term 072)
Saturday 22-3-2008
35 Minutes
Student Name
ID #
A
Fill the following table
Substance
H2O
H2O
H2O
R134a
R134a
T, oC
350
v, m3/kg
-20
P, kPa
2000
125
8200
160
500
Substance
H2O
H2O
H2O
R134a
R134a
T, oC
350
105
360
-15.6
-20
P, kPa
2000
125
8200
160
500
v, m3/kg
0.1386
1.62
0.02997
0.025
0.0007356
360
* quality not defined
u kJ/kg
x
Phase description
1
2645
0.025
u kJ/kg
2859
2507
2645
68.65
25.26
X
Phase description
Superheated vapor
1
Saturated vapor
Superheated vapor
0.1975 Saturated mixture
Compressed liquid
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 3 (Term 072)
Saturday 26-4-2008
20 Minutes
Student Name
ID #
A
A steam turbine receives water at 15 MPa, 600 oC at a rate of 100 kg/s, as shown in
figure. In the middle section, 20 kg/s is withdrawn at 2 MPa, 350 oC, and the rest exits
the turbine at 75 kPa, and 95% quality. Assume no heat transfer and no changes in
kinetic energy, find the total turbine power.
Steam
(1)
W
(2)
(3)
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 3 (Term 072)
Saturday 26-4-2008
20 Minutes
Student Name
ID #
B
A steam turbine receives water at 12.5 MPa, 600 oC at a rate of 100 kg/s, as shown in
figure. In the middle section, 20 kg/s is withdrawn at 3 MPa, 400 oC, and the rest exits
the turbine at 100 kPa, and 95% quality. Assume no heat transfer and no changes in
kinetic energy, find the total turbine power.
Steam
(1)
W
(2)
(3)
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 3 (Term 072)
Saturday 26-4-2008
20 Minutes
Student Name
ID #
A
Two steady flows of air enter a control volume (device), one is 0.025 lg/s, flowing at
350 kPa and 150 oC (State 1). The other enters at 350 kPa and 15oC (State 2), both at
low velocity. A single flow of air exits at 100 kPa. A single flow of air exits at 100
kPa, -40 oC through a 25 mm diameter pipe (state 3). The control volume rejects 1.2
kW heat to the surroundings and produces 4.5 kW of power. Determine the mass flow
rate of inlet at state (2).
(1)
(3)
(2)
Q
W
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 4 (Term 072)
Saturday 17-5-2008
30 Minutes
Student Name
ID #
A
An insulated vertical piston cylinder device initially contains 0.2 m3 of air at 200 kPa
and 22oC. At this state, a linear spring touches the piston but exerts no force on it. The
cylinder is connected by a valve to a line that supplies air at 800 kPa and 22 oC. The
valve is opened, and air from the high pressure line is allowed to enter the cylinder.
The valve was turned off when the pressure inside the cylinder reaches 600 kPa. If the
enclosed volume inside the cylinder doubles during this process, determine
1. The mass of air that entered the cylinder
2. The final temperature of the air inside the cylinder.
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics
Quiz # 4 (Term 072)
Saturday 17-5-2008
30 Minutes
Student Name
ID #
B
A 0.11-m3 rigid tank contains saturated refrigerant- 134a at 700 kPa. Initially, 20 percent of
the volume is occupied by liquid and the rest by vapor. A valve at the top of the tank is now
opened, and vapor is allowed to escape slowly from the tank. Heat is transferred to the
refrigerant such that the pressure inside the tank remains constant. The valve is closed when
the last drop of liquid in the tank is vaporized.
Determine the total heat transfer for this process.
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
ME203 Thermodynamics I
Quiz # 3 (Term 061)
Wednesday 13-12-2006
20 Minutes
Student Name
ID #
An insulated, vertical piston–cylinder device initially contains 10 kg of water, 6 kg of
which is in the vapor phase. The mass of the piston is such that it maintains a constant
pressure of 200 kPa inside the cylinder. Now steam at 0.5 MPa and 350°C is allowed
to enter the cylinder from a supply line until all the liquid in the cylinder has
vaporized. Determine (a) the final temperature in the cylinder and (b) the mass of the
steam that has entered.
King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
Thermodynamics I (ME203)
Quiz 5
Duration: 30 minutes
Wednesday 4th June 2008.
Student Name
Student ID #
A cylinder/piston contains 3 kg of water at 500 kPa, 600C. The piston has a crosssectional area of 0.1 m2 and is restrained by a linear spring with spring constant 10
kN/m. The setup is allowed to cool down to room temperature due to heat transfer to
the room at 20C.
i.
Calculate v1, u1, s1.
Superheated steam
V1 = 0.8041 m3/kg
u1 = 3300 kJ/kg
s1 = 8.352 kJ/kg K
ii.
If the second state represents saturated mixture of liquid and vapor, calculate
v2, u2, s2.
One state on the linear PV relation is given (state 1) and the slope (k/A2)
P 1 = A + B v1
P2 = A + B v2
Thus, A = 0.1 and B = 10/(0.12)
Therefore, P2 = 2.339 kPa
And v2 = 0.2239 m3/kg
This leads to: x2 = 0.003858
u2 = 92.78 kJ/kg
s2 = 0.3285 kJ/kg
K
iii.
Calculate the work done in this process.
w = (P1+p2) *(v2 – v1)/2 = -145.7 kJ/kg
W = m w = -437.2 kJ
iv.
Calculate the heat transferred during in this process.
Q = m (w + u2 – u1) = -10059 kJ
v.
Calculate the total entropy change for this process.
System: Ssys = m (s2 – s1) = -24.07 kJ/K
Surroundings Ssurr = Qsurr/T = +10059/(20+273) = 34.44 kJ/K
Stotal = 10.26 kJ/K