Chapter 15
Varied Flow in Open
Channels
Problem 15.1
Water ows in a circular concrete pipe (Mannings q = 0=012) with a depth that is
half of the pipe diameter (0.8 m). If the slope is 0.004, nd the ow rate.
Solution
The ow rate is obtained from the Chezy
Chapter 14
Turbomachinery
Problem 14.1
A propeller is to be selected for a light airplane with a mass of 1500 kg which
will cruise at 100 m/s at an altitude where the density is 1 kg/m3 The lift-to-drag
ratio at cruise conditions is 30:1, and the engine r
Chapter 13
Flow Measurements
Problem 13.1
Velocity in an air ow is to be measured with a stagnation tube that has a resolution of 0.1-in. H2 O. Find the minimum uid speed in ft/s that can be measured.
Neglect viscous eects and assume that the air is at ro
Chapter 12
Compressible Flow
Problem 12.1
Methane at 25o C (U = 518 J/kg/K, n = 1=31) is owing in a pipe at 400 m/s.
Is the ow subsonic, sonic, supersonic, or hypersonic?
Solution
The speed of sound in methane is
s
s
f = nUW = 1=31 518 298
= 450 m/s
Becau
Chapter 11
Drag and Lift
Problem 11.1
Air with a speed of Yr ows over a long bar that has a 15r wedge-shaped crosssection. The pressure variation, as represented using the coe!cient of pressure, is
shown in the following sketch. On the west face of the ba
Chapter 10
Flow in Conduits
Problem 10.1
Water at 20o C ( = 10 3 Ns/m2 , = 1000 kg/m3 ) ows through a 0.5-mm tube
connected to the bottom of a reservoir. The length of the tube is 1.0 m, and the
depth of water in the reservoir is 20 cm. Find the ow rate i
Chapter 9
Surface Resistance
Problem 9.1
An aluminum cube of density 2700 kg/m3 slides with a constant speed of 20 cm/s
down a plate that is at an angle of 30r with respect to the horizontal. The plate is
covered with a stationary layer of 0.1-mm-thick oi
Chapter 8
Dimensional Analysis and
Similitude
Problem 8.1
The discharge, T> of an ideal uid (no viscous eects) through an orice depends
on the orice diameter, g, the pressure drop across the orice, s, and the uid
density. Find a nondimensional relationshi
Chapter 7
Energy Principle
Problem 7.1
Air ows through a rectangular duct of dimension 1 ft 5 ft. The velocity prole
is linear, with a maximum velocity of 15 ft/s. Find the kinetic energy correction
factor.
Solution
The kinetic energy correction factor is
Chapter 6
Momentum Principle
Problem 6.1
Water at 20o C is discharged from a nozzle onto a plate as shown. The ow rate of
the water is 0.001 m3 @s, and the diameter of the nozzle outlet is 0.5 cm. Find the
force necessary to hold the plate in place.
Solut
Chapter 5
Control Volume Approach
and Continuity Principle
Problem 5.1
A 10-cm-diameter pipe contains sea water that ows with a mean velocity of 5
m/s. Find the volume ow rate (discharge) and the mass ow rate.
Solution
The discharge is
T=YD
where Y is the
Chapter 4
Flowing Fluids and Pressure
Variation
Problem 4.1
A ow moves in the cfw_-direction with a velocity of 10 m/s from 0 to 0.1 second
and then reverses direction with the same speed from 0.1 to 0.2 second. Sketch
the pathline starting from cfw_ = 0
Chapter 3
Fluid Statics
Problem 3.1
For a lake, nd the depth k at which the gage pressure is 1 atmosphere.
specic weight of water is 62.3 lbf/ft3 .
The
Solution
At the free surface of the lake, pressure will be ssurface = 1=0 atm absolute or 0.0
atm gage.
Chapter 2
Fluid Properties
Problem 2.1
Calculate the density and specic weight of nitrogen at an absolute pressure of
1 MPa and a temperature of 40r C.
Solution
Ideal gas law
=
s
UW
From Table A.2, U = 297 J/kg/K. The temperature in absolute units is W =
Chapter 1
Introduction
Problem 1.1
Consider a glass container, half-full of water and half-full of air, at rest on a laboratory table. List some similarities and dierences between the liquid (water) and
the gas (air).
Solution
Similarities
1. The gas and