Faculty of Engineering
DEPARTMENT OF MECHANICAL ENGINEERING
ME 311 Fluid Mechanics
Homework Assignment No 2
Name:……………………………………………………………………
I.D # :……………………………………………………………………..
Due Date 17/03/2015
Problem 1
A person thrusts his hand into the water while traveling 3 m/s in a motorboat. What is the maximum pressure on
his hand?
Problem 2
. (2)
Water flows from a pressurized tank, through a 3 cm
diameter pipe, exits from a 1 cm diameter nozzle, and
rises 10 m above the nozzle as shown in the figure.
Determine the pressure in the tank if the flow is
steady, frictionless, and incompressible.
10 m
(1)
1 cm
.
1m
3 cm
Problem 3
Air flows through a Venturi channel of rectangular
cross section as shown in the figure. The constant
width of the channel is 0.06 m and the height at the
exit is 0.04 m. Compressibility and viscous effects are
negligible.
(a) Determine the flowrate when water is drawn up
0.10 m in a small tube attached
to the static pressure tap at the throat where the
channel height is 0.02 m.
(b) Determine the channel height, h2, at section (2)
where, for the same flowrate as in part (a), the water is
drawn up 0.05 m.
(c) Determine the pressure needed at section (1) to
produce this flow.
Problem 4
An air cushion vehicle is supported by forcing air into
the chamber created by a skirt around the periphery of
the vehicle as shown in the figure. The air escapes
through the 7 cm clearance between the lower end of the
skirt and the ground. Assume the vehicle weighs 50 kN
and is essentially rectangular in shape, 9 by 20 m. The
volume of the chamber is large enough so that the
kinetic energy of the air within the chamber is
negligible. Determine the flowrate, Q, needed to support
the vehicle. If the ground clearance were reduced to 5
cm, what flowrate would be needed? If the vehicle
weight is reduced to 25 kNand the ground clearance
maintained at 7 cm, what flowrate would be needed?
7 cm
Problem 5
A conical plug is used to regulate the air flow from the pipe shown in the figure. The air leaves the edge of the
cone with a uniform thickness of 0.02 m. If viscous effects are negligible and the flowrate is 0.5 m3/s determine
the pressure within the pipe.