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FLUID MECHANICS 1

ME 251Lecture 1

Course Policy and Introductory Lecture

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Course Policy

LecturerD. A. Quansah, MSc, MSpe

Teaching Assistant/Demonstrator

to be introduced later

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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.

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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.

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Course Policy

Office Hours

By appointment!!!Correspondence

Correspondences shall be by email, and sent to

daquansah.coe@knust.edu.gh

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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

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Course Policy

Class Attendance

Class attendance is compulsory !!!

A student shall be deemed absent

if he/she reports 20 mins into the

class

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Course Policy

General Comportment

decent conduct (both in dressing

and demeanour)

The lecturer reserves the right to

use appropriate sanctions whennecessary.

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Lecture 1Fluid and its properties

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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.

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Fluid and its properties

Hydraulics Hydrology AerodynamicsBio-fluid

mechanicsetc

Fluid Mechanics

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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)

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Fluid and its propertiesprimary and Secondary dimensions

Primary dimensions are the most fundamental dimensions

from which all other dimensions are defined

E.g.

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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.

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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

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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?

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Fluid and its propertiesDensity

The mass per unit volume of material is

called the density, which is generally

expressed by the symbol.

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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?

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