MOI UNIVERSITY
DEPARTMENT 0F MECHANICAL & PRODUCTION ENGINEERING
MPE 232 : FLUID MECHANICS I
CAT 2 DATE: April 30, 2023.
Attempt ALL questions.
1. The diameter of a cylindrical water tank is Do and its height is H. The tank is filled
with water, which is open to the atmosphere. An orifice of diameter Do with a
smooth entrance (i.e., no losses) is open at the bottom. Develop a relation for the
time required for the tank
a) to empty halfway and
b) to empty completely.
2. Water enters a tank of diameter DT steadily at a mass flow rate of m in. An orifice at
the bottom with diameter Do allows water to escape. The orifice has a rounded
entrance, so the frictional losses are negligible. If the tank is initially empty,
a) determine the maximum height that the water will reach in the tank and
b) obtain a relation for water height z as a function of time.
3. Firefighters are holding a nozzle at the end of a hose while trying to extinguish a fire.
If the nozzle exit diameter is 6 cm and the water flow rate is 5 m3/min, determine
a) the average water exit velocity and
b) the horizontal resistance force required of the firefighters to hold the nozzle.
4. Consider water at 20°C flowing in a the three-reservoir system. The system data are
as follows:
Elevations Z1 = 6 m Z2 = 30 m Z3 = 15 m
Pipe diameters D1 = 200 mm D2 = 150 mm D3 = 230 mm
Pipe lengths L1 = 550 m L2 = 370 m L3 = 300 m
All pipes are galvanized iron. Compute the flow rate in all pipes.
5. A thin plate 100 cm long and 30 cm wide moves at 3 m/s through water. The
boundary layer is 6 cm thick at the rear of the plate. The velocity distribution is
given by:
1
V y 4
V
Determine the resistance on the plate.
DEPARTMENT 0F MECHANICAL & PRODUCTION ENGINEERING
MPE 232 : FLUID MECHANICS I
CAT 2 DATE: April 30, 2023.
Attempt ALL questions.
1. The diameter of a cylindrical water tank is Do and its height is H. The tank is filled
with water, which is open to the atmosphere. An orifice of diameter Do with a
smooth entrance (i.e., no losses) is open at the bottom. Develop a relation for the
time required for the tank
a) to empty halfway and
b) to empty completely.
2. Water enters a tank of diameter DT steadily at a mass flow rate of m in. An orifice at
the bottom with diameter Do allows water to escape. The orifice has a rounded
entrance, so the frictional losses are negligible. If the tank is initially empty,
a) determine the maximum height that the water will reach in the tank and
b) obtain a relation for water height z as a function of time.
3. Firefighters are holding a nozzle at the end of a hose while trying to extinguish a fire.
If the nozzle exit diameter is 6 cm and the water flow rate is 5 m3/min, determine
a) the average water exit velocity and
b) the horizontal resistance force required of the firefighters to hold the nozzle.
4. Consider water at 20°C flowing in a the three-reservoir system. The system data are
as follows:
Elevations Z1 = 6 m Z2 = 30 m Z3 = 15 m
Pipe diameters D1 = 200 mm D2 = 150 mm D3 = 230 mm
Pipe lengths L1 = 550 m L2 = 370 m L3 = 300 m
All pipes are galvanized iron. Compute the flow rate in all pipes.
5. A thin plate 100 cm long and 30 cm wide moves at 3 m/s through water. The
boundary layer is 6 cm thick at the rear of the plate. The velocity distribution is
given by:
1
V y 4
V
Determine the resistance on the plate.
