ENGG1800 Introduction to Engineering Lecture 4: Fluid Mechanics

Introduction to Engineering Concepts

ENGG1800
Introduction to Engineering
Lecture 4: Fluid Mechanics
Dr Mohamed N. Marei
March 2024
Textbook: Introduction to Fluid Mechanics (9th Ed.) by Philip J. PritchardIntroduction to Engineering
Materials
Mechanics
Energy
Mohamed Marei
ENGG1800- Introduction to Engineering
2025Introduction to Engineering
Materials
Mechanics
Body Statics
Body Dynamics
Fluid Statics
Energy
Fluid Dynamics
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Fluid Mechanics Topics

• Definition of Fluid Mechanics
• Applications of Fluid Mechanics
• Definition of Fluid Statics
• Applications of Fluid Statics
• Density and pressure
• Viscosity
• Surface tension
• Hydraulic pressure and forces
• Buoyancy

Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Definition of Fluid Mechanics

Fluids can be divided into liquids and gases.
They can flow and do not have a definite shape, as the molecules are not held
together.
Static
deflection
-
A
1
Solid
1
Free
surface
A
A
Liquid
Gas
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Fluid Definition and Properties

A fluid is a substance that can flow and take the shape of its container. Fluids
can include both liquids and gases, as they share common properties such as
the ability to flow and the absence of a definite shape. The molecules or
particles of a fluid are not held together in a fixed position but rather move
freely, allowing the fluid to take on the shape of its container. This property is
known as fluidity, and it distinguishes fluids from solids, which have a fixed
shape and are not easily deformed. Examples of fluids include water, air, oil,
and natural gas.
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Fluid Mechanics Overview

• Definition of Fluid Mechanics
• Applications of Fluid Mechanics
• Definition of Fluid Statics
• Applications of Fluid Statics
• Density and pressure
• Viscosity
• Surface tension
• Hydraulic pressure and forces
• Buoyancy

Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Applications of Fluid Mechanics in Civil Engineering

Water Engineering Applications

• Water Engineering
• Water supply
• Drainage and waste systems
• Storm water
  Urban Wet Weather Flows
  CEPA
  Industrial
  Wastewater
  Street
  Catch LO
  Basin
  Industrial
  Wastewater
  Sanitary
  Wastewater
  Bedst Snow
  Melt
  Sanitary Wastewater
  Separate+
  Storm Sewer
  System
  Combined
  Sewer System
  Control
  Device
  Sumę
  Pump
  Sanitary
  Wastewater
  Intercep for
  Sower
  In flow
  Separate Sanitary
  Sewer System
  Infiltration
  Sanitary
  Sewer
  Overflows
  Greise
  Blockage
  Headworks
  Sanitary
  Sewer
  Overflows
  Wastewater
  Treatment Plant
  Storm Water
  Point Source
  Combined
  Sewer
  Overflow
  Bypass
  Erosion
  CSO-Related
  Bypass
  Fully
  Treated
  Effluent
  NAM CARE
  Non-Point
  Source Pollution
  This Photo by Unknown Author is licensed under CC BY-SA-NC
  Mohamed Marei
  ENGG1800- Introduction to Engineering
  2025
  Storm Water

Applications of Fluid Mechanics in Mechanical Engineering

• Pipelines
• Pumps and Compressors
• Hydraulic machinery
• HVAC
• Automotive Aerodynamics
  This Photo by Unknown Author is licensed under CC BY-SA
  Mohamed Marei
  ENGG1800- Introduction to Engineering
  2025

Applications of Fluid Mechanics in Aerospace Engineering

• Aircraft design
• Rockets and Space shuttles
• Jet engines
  ...
  QANTAS
  of Australia
  .........
  ......
  F
  @ United States
  NASA
  This Photo by Unknown Author is licensed under CC BY-SA
  Mohamed Marei
  ENGG1800- Introduction to Engineering
  2025

Applications of Fluid Mechanics in Biomedical Engineering

• Blood flow in the circulatory system
• Air flow in the respiratory system
• Fluid flow in the digestive system
• Medical Infusion pumps
  Blood Flow of the Human Heart
  =
  oxygenated blood
  to upper body
  deoxygenated blood
  from upper body
  deoxygenated
  blood to lungs
  deoxygenated
  blood to lungs
  oxygenated blood
  from lungs
  oxygenated blood
  from lungs
  deoxygenated blood
  from lower body
  oxygenated blood
  to lower body
  A
  P
  ZA MARIEN CLOSE ALL CLAMP, FORE OPENING DOON
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  50
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  mithr
  133.7
  Vol Inf
  44.
  Concurrent
  Select Line A/B to program
  Select STOP key to Clear
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  Standby
  A
  B
  Vols/CCA
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  2
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  4
  5
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  icumedical
  Plum360
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  CLEAR
  LOCKE KEYPAD
  Follow instructions for use. The System Operating Manual
  contains proper use, warnings, and cautions.
  This Photo by Unknown Author is licensed under CC BY-SA
  Mohamed Marei
  ENGG1800- Introduction to Engineering
  2025

Applications of Fluid Mechanics in Energy Engineering

• Wind turbines
• Internal combustion engines
• Gas turbines
  Oil Inlet
  Turbine Wheel
  Compressor Wheel
  Exhaust Gas
  Discharge
  Intake System
  Attaches Here
  Wastegate
  Ambient Air Inlet
  Hot Exhaust Gasses
  Compressed Air Flow
  Oil Outlet
  Charge Air Cooler
  Engine Cylinder
  This Photo by Unknown Author is licensed under CC BY-SA
  Mohamed Marei
  ENGG1800- Introduction to Engineering
  2025

Applications of Fluid Mechanics in Chemical and Electrical Engineering

Chemical Engineering Applications

• Process design
• Flow measurement
• Reaction rates
• Mass and energy balance

Electrical Engineering Applications

• Power generation from wind
  turbines and nuclear plants
• Cooling of transformers
• Power wiring between towers

Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Methods of Analysis in Fluid Mechanics

Analytical and Numerical Analysis

• Analytical analysis
• Numerical analysis
• Experimental analysis
  Apps to try:
  Wind tunnel app
  Ansys (Fluent)
  Image of a stagnation flame. The
  flow is seeded with 1 micron Al2O3
  particles.
  Alternative Fuels Lab, McGill
  University (2008).
  Flow visualisation by smoke
  streaklines. Symmetric airfoil at a
  large angle of attack leading to a
  stall.
  Mohamed Marei
  ENGG1800- Introduction to Engineering
  2025

Methods of Analysis: Flow Transition

Laminar to Turbulent Flow Transition

Laminar to
Turbulent Flow
Transition in a
Pipe
Toronto
Metropolitan
University
vorare
400.0
210
20 0
GALLERY OF FLUID MOTION
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Methods of Analysis: Fluid Motion Gallery

GALLERY OF FLUID MOTION
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Fluid Mechanics and Statics Topics

• Definition of Fluid Mechanics
• Applications of Fluid Mechanics
• Definition of Fluid Statics
• Applications of Fluid Statics
• Density and pressure
• Viscosity
• Surface tension
• Hydraulic pressure and forces
• Buoyancy

Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Definition of Fluid Statics

Fluid statics is a branch of fluid mechanics that deals with the
behaviour of fluids at rest, or in a state of equilibrium. It studies the
forces acting on fluids at rest, such as pressure and buoyancy, and
their effects on objects immersed in the fluid.
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Fluid Mechanics and Statics Overview

• Definition of Fluid Mechanics
• Applications of Fluid Mechanics
• Definition of Fluid Statics
• Applications of Fluid Statics
• Density and pressure
• Viscosity
• Surface tension
• Hydraulic pressure and forces
• Buoyancy

Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Applications of Fluid Statics

Hydraulic Systems and Design

Hydraulic systems: Fluid statics is used in hydraulic
systems to calculate the pressure exerted by fluids on
pistons, cylinders, and other hydraulic components.
Design of ships and submarines: Fluid statics play an
important role in the design of ships and submarines by
determining the buoyancy and stability of the vessels.
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Applications of Fluid Statics in Construction and Measurement

Construction and Pressure Measurement

Construction of dams and bridges: Fluid statics is used in the design and
construction of dams and bridges to determine the forces acting on the
structures and to ensure their stability.
Measurement of atmospheric pressure: Fluid statics is used in
barometers to measure atmospheric pressure, which is an important
parameter in weather forecasting.
Design of pressure vessels: Fluid statics is used in the design of pressure
vessels to ensure that they can withstand the pressure exerted by the
fluids they contain.
111
SWE
Jas
this Photo is licensed under CC
CC BY-SA
Mohamed Marei
ENGG1800- Introduction to Engineering

Fluid Mechanics and Statics Topics Revisited

• Definition of Fluid Mechanics
• Applications of Fluid Mechanics
• Definition of Fluid Statics
• Applications of Fluid Statics
• Density and pressure
• Viscosity
• Surface tension
• Hydraulic pressure and forces
• Buoyancy

Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Density and Pressure Concepts

Definition of Density

Density is a physical quantity that measures the
amount of mass per unit volume of a substance.
It is defined as the mass of a substance divided by
its volume:
Density = Mass / Volume
p=m/V
"Point" C at x,y,z
Volume 8V
of mass 8m
y
x
-
(a)
www.chem.uiuc.edu
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Density and Specific Gravity

Specific Gravity Calculation

Specific Gravity (SG) is the ratio of the
density of a substance to the density of a
reference substance (usually water).
Specific Gravity(SG) =
Density of Substance
Density of Water
The density of mercury is
13600 kg/m3. It's 13.6 times
the density of water.
SGhg=13.6
hg
13.6 cm3 water
1 cm3 mercury
www.chem.uiuc.edu
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Pressure Definition and Formula

Fluid Pressure Calculation

Pressure is the force per unit area exerted by a fluid on the walls of its
container or any object immersed in it. It is the result of the random motion
and collisions of the fluid molecules with each other and with the surface of
the container or object.
Fluid pressure can be calculated using the formula:
Pressure = Force/Area
P=F/A
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Pressure in Static Fluids

Weight of Fluid Column

Pressure in a static fluid is the weight of the fluid column divided by the
area.
Think about:
- When you climb a mountain
- When you dive into the ocean
- When using a barometer
World's record free dive
https://www.youtube.com/watch?v=PUcpzf0rbAw
Vacuum
Glass
Tube
Mercury
Scale
AIr
Pressure
AIr
Pressure
Reservoir
This Photo by Unknown
Author is licensed under CC
BY-SA
Mohamed Marei
ENGG1800- Introduction to Engineering
2025

Pressure Calculation in Liquids

Formula for Liquid Pressure

P= Fluid Weight/ Area
P= mg/A
P=p Vg/A
P= pg(h.A) / A
P= pgh
Vacuum
Glass
Tube
.
Mercury
Scale
h
Pressure
Air
Pressure
Reservoir
Can we use water instead of Mercury?
This Photo by Unknown
Author is licensed under CC
BY-SA
Mohamed Marei
ENGG1800- Introduction to Engineering
2025
P
Liquid