Post on 06-Apr-2018
transcript
8/2/2019 ME 251 Lecture 1
1/20
FLUID MECHANICS 1
ME 251Lecture 1
Course Policy and Introductory Lecture
8/2/2019 ME 251 Lecture 1
2/20
Course Policy
LecturerD. A. Quansah, MSc, MSpe
Teaching Assistant/Demonstrator
to be introduced later
8/2/2019 ME 251 Lecture 1
3/20
Course Policy
Course OutlineFluid and its properties,
Fluid Statics,
Kinematics and Dynamics of fluid flow,
Introduction to steady incompressibleflow in pipes,
Ducts and open channels.
8/2/2019 ME 251 Lecture 1
4/20
Course Policy
Useful References Books1. Cengel, Y. A., & Turner, R. A. (2001). Fundamentals
of Thermal-Fluid Sciences. New York: McGraw-HillCompanies Inc.
2. Crowe, C., & Elger, D. (2009). Engineering FluidMechanics. John Wiley & Sons, Inc.
3. Fox, R. W., McDonald, A. T., & Pritchard, P. J.(2004). Introduction to Fluid Mechanics (SixthEdition ed.). Bogota: John Wiley & Sons, Inc.
4. NAKAYAMA, Y. (2000). Introduction to FluidMechanics. Tokyo: Yokendo Co. Ltd.
8/2/2019 ME 251 Lecture 1
5/20
Course Policy
Office Hours
By appointment!!!Correspondence
Correspondences shall be by email, and sent to
daquansah.coe@knust.edu.gh
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
6/20
Course Policy Course Assessment Class attendance (over 80%
attendance) 5 marks
Class assignments and quizzes 10marks
Mid-semester examinations
15marks
End-of-Semester examination 70
marks
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
7/20
Course Policy
Class Attendance
Class attendance is compulsory !!!
A student shall be deemed absent
if he/she reports 20 mins into the
class
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
8/20
Course Policy
General Comportment
decent conduct (both in dressing
and demeanour)
The lecturer reserves the right to
use appropriate sanctions whennecessary.
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
9/20
8/2/2019 ME 251 Lecture 1
10/20
Lecture 1Fluid and its properties
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
11/20
Fluid and its properties
What is a fluid?A fluid is a substance that deforms
continuously under the applicationof a shear (tangential) stress no
matter how small the shear stressmay be.
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
12/20
Fluid and its properties
Hydraulics Hydrology AerodynamicsBio-fluid
mechanicsetc
Fluid Mechanics
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
13/20
Fluid and its propertiesUnits and DimensionsA dimension is a category that represents a physical quantitysuch as mass, length, time, momentum, force, acceleration,
and energy.
Dimension Symbol Unit (SI) Symbol Unit (SI)Length L meter (m)
Mass M kilogram (kg)
Time T second (s)
Temperature kelvin (K)Electric current i ampere (A)
Amount of light C (cd)
Amount of matter N mole (mol)
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
14/20
Fluid and its propertiesprimary and Secondary dimensions
Primary dimensions are the most fundamental dimensions
from which all other dimensions are defined
E.g.
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
15/20
Fluid and its propertiesUnits
While a dimension expresses a specific
type of physical quantity, a unit assigns a
number so that the dimension can be
measured. For example, measurement of
volume (a dimension) can be expressedusing units of liters.
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
16/20
Fluid and its propertiesUnit Systems
The system in which length, mass and
time are adopted as the basic quantities,
and from which the units of otherquantities are derived, is called the
absolute system of units
Other systems chose as basic quantities:
Force [F], length [L], time [t], temperature [T].
Force [F], mass [M], length [L], time [t], temperature [T]
See notes for some examples
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
17/20
Fluid and its propertiesDimensional Homogeneity
When the primary dimensions on each
term of an equation are the same, the
equation is dimensionally homogeneous.
How? Why?
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
18/20
Fluid and its propertiesDensity
The mass per unit volume of material is
called the density, which is generally
expressed by the symbol.
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
19/20
Fluid and its propertiesSpecific Gravity
The ratio of the density of a material to
the density of waterw, is called the
specific gravity, which is expressed by thesymbol s
Unit?
mailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.ghmailto:daquansah.coe@knust.edu.gh8/2/2019 ME 251 Lecture 1
20/20