# SUGGESTED MINIMUM KNOWLEDGE OF FLUID MECHANICS AND FOR FE EXAM

Mechanics

Oct 24, 2013 (4 years and 8 months ago)

1,407 views

SUGGESTED MINIMUM
KNOWLEDGE OF FLUID
MECHANICS AND
HEAT TRANSFER

FOR FE EXAM

F. Parsi

Winona State University

March 5, 2013

2 Hour Review

http://www.ncees.org/exams/study_materials/fe_handbook/

Exam Composition

Morning

120 Questions

4 hours

7% Fluid Mechanics

Afternoon (General Engineering)

60 Questions

15% Fluid Mechanics

Define and/or Explain

density

specific gravity

specific volume

pressure (absolute and gage)

vapor pressure

stress tensor

shear stress

shear rate

viscosity (dynamic and kinematic)

Newtonian and non
-
Newtonian fluids

dimensional analysis

Fluid Statics

u
-
tube manometer calculations

barometer calculations

hydrostatic pressure

force on submerged flat surface

point of application of the force

force on submerged curved surfaces

hydraulic ram

Archimedes's principle buoyancy

Fluid Dynamics

Reynolds number and its significance

laminar and turbulent flow

velocity distribution

conservation of mass (continuity equation)

Bernoulli equation

major head loss calculations in pipes

friction factors (Moody and Darcy)

minor head loss calculations in piping systems

pumping power calculation

drag coefficient and drag force

Fluid Measurement Devices

pitot tube

venturi meters

orifices

Example 1: Pressure

What is the atmospheric pressure on the
planet if the absolute pressure is 100 kPa
and a gage pressure is 10 kPa?

1. 10 kPa

2. 80 kPa

3. 90 kPa

4. 100 kPa

Example 2: static Pressure

What is the height of a column of tetrachloride
with a specific gravity of 1.56 that supports a
pressure of 1 lbf/in
2
?

1.
0.01 ft

2.
0.12 ft

3.
1.48 ft

4.
1.56 ft

5.
2.31 ft

Example 3: Viscosity

Kinematic viscosity cabn be expressed in
which of the following units?

1. m
2
/s

2. s
2
/m

3. kg.s
2
/m

4. kg/s

Example 4: Hydrostatic
Pressure

A pressure of 35
kPa

is measured 4 m
below the surface of an unknown liquid.
What is the specific gravity of the liquid?

1.
0.09

2.
0.89

3.
0.93

4.
1.85

Example 5: u
-
tube manometer

The specific gravity of mercury is 13.6, and the
specific gravity of
glycerine

is 1.26. For the
manometer shown, calculate the difference in
pressure between points A and B.

1.
35
kPa

2.
42
kPa

3.
55
kPa

4.
110
kPa

Example 6: U
-
Tube Manometer

The fluid in a manometer tube is 60% water
and 40% alcohol (specific gravity = 0.8). What
is the manometer fluid height difference if a 6.2
lbf/in2 pressure difference is applied across
the two ends of manometer?

1.
0.92 in

2.
15.5 in

3.
186 in

4.
215 in

5.
361 in

Example 7: Fluid Statics

What is the resultant force on the inclined
wall?

1.
222
kN

2.
395
kN

3.
503
kN

4.
526
kN

Example 8: Fluid Statics

What is the vertical force on the inclined
wall?

1.
197
kN

2.
392
kN

3.
486
kN

4.
544
kN

Example 9: Hydrostatic Force

A tank is filled with water to a depth of 10
ft. What is the total force on the gate?

1.
560 lbf

2.
5400 lbf

3.
5620 lbf

4.
6000 lbf

5.
6240 lbf

Example 10: Buoyancy

A crown is made of an alloy of gold and silver.
The crown weighs 1000 g in air and 940 g in
water. What percentage of gold was it? Density
of gold and silver are respectively 19.3 g/cm
3

and 10.5 g/cm
3
.

1.
53.1%

2.
67.4%

3.
81.2 %

4.
91.3%

Example 11: Buoyancy

A 24
-
in
-
long rod floats vertically in water. It has
a 1
-
in
2
cross section and a specific gravity of
0.6. What length L, is submerged?

1.
2.4 in

2.
9.6 in

3.
14.4 in

4.
18.0 in

5.
18.7 in

Example 12: Fluid Dynamics

Consider water flowing through a converging
channel as shown and discharging freely into
the atmosphere at the exit. What is the gage
pressure at the inlet? Assume the flow to be
incompressible and frictionless.

1.
102
kPa

2.
106
kPa

3.
113
kPa

4.
127
kPa

Example 13: Dimensionless
Numbers

A 500
-
ft
-
long surface vessel is modeled at
1:50. What speed must the model travel if a 25
mph similarity is desired?

1.
3.54 ft/sec

2.
5.0 ft/sec

3.
5.2 ft/sec

4.
7.07 ft/sec

5.
7.3 ft/sec

1.
The mean radius of the pipe

2.
The radius of the pipe bend on the line

3.
The wetted perimeter of a conduit divided
by the area of the flow

4.
The cross
-
sectional fluid area divided by
wetted perimeter

What is the hydraulic radius of the shown
open channel?

1.
b/4

2.
b/3

3.
b/2

4.
2b/3

Example 16: Pipe flow

A steel pipe with an inside diameter of 25 mm is
20 m long and carries water at a rate of 4.5
m3/h. Assuming the specific roughness of the
pipe is 0.00005 m, the water has an absolute
viscosity of 1.00 x 10
-
3 m2/s and a density of
1000 kg/m3, what is the friction factor?

1.
0.023

2.
0.024

3.
0.026

4.
0.028

What is the expected head loss per mile of
closed circular pipe (17
-
in inside diameter,
friction factor of 0.03) when 3300 gal/min of
water flow under pressure?

1.
0.007 ft

2.
0.64 ft

3.
38 ft

4.
3580 ft

5.
1.9x10
7

ft

Example 18: Pipe Flow

The transition between laminar and turbulent
flow in a pipe usually occurs at a Reynolds
number of approximately

1.
900

2.
1200

3.
1500

4.
2100

5.
3900

Example 19: Pumping Power

A pump requires 75 kW to move water with a
specific gravity of 1.0 at a certain flow rate to a
given elevation. What power does the pump
require if the flow rate and elevation conditions
are the same, but the fluid pumped has a
specific gravity of 0.8?

1.
45 kW

2.
60 kW

3.
75 kW

4.
90 kW

Basic Heat Transfer

Conduction

Convection