Introduction to Fluid Mechanics Property of Fluid Mechanics

Introduction to Fluid MechanicsProperty of Fluid Mechanics

Instructor: Sara Serwer Youns

Email:[email protected]

Tishk International University

Mechatronics Engineering Department

Fluid Mechanics

Week 1Lecture 1: 5/10 /2021

Week 1Lecture 2: 6/10 /2021

Outline

• Students Obligation

• Syllabus

• Assessment

• Introduction

• Property of Fluid ;

1. Density or mass density

2. Specific weight or weight density

3. Specific volume

4. Specific gravity

Students Obligation

• attending classes on time and regularly.

• being prepared for classes with all necessary supplies.

• Students need to respect the ideas and opinions of their classmates in and outside of the classroom.

• If you are more than 10 minutes late, you will be declared absent.

• The homework and assignments should be submit it on time .

• The students have to participate all quizzes and exams

• The students have to have scientific calculator

Assessment

Objectives and outcomes of this course

Fluid

• fluid is a substance that deforms continuously under the action of an applied shear force or stress - A fluid is a substance that can resist shear only when moving.

Fig:describe that fluid take the shape of the vessel

Fluid Mechanics

What are the common Examples for fluid

• Gases are fluids that do not have a definite volume. A gas has no shape and it assumes the volume of the container that it is confined in. Gases can be compressed. They are affected by temperature and pressure.

• Liquid: It is an incompressible fluid, which means that a given mass of liquid will fill a set volume regardless of container size.

What are the differences between liquid and gases.

Video

Video on gas does not have fixed volume and shape(3)

Application of fluid Mechanics

Property of Fluid

• Properties of fluids ultimately determine the design of ships, airplanes, cars, and hydraulic machines.

What are the common properties of fluid

• Density or mass density

• Specific weight or weight density

• Specific volume

• Specific gravity

Density

• Sometimes you can compare the densities of substances just by observing them.

• For example, suppose you have a solid block of wood, and a solid block of gold.

• When you drop each block into a tub of water, the wood floats and the gold sinks.

Density

• The density of water is 1.0 g/cm3.

• You can conclude that the wood has a density lower than 1.0g/cm3.

• In contrast, the density of the gold is greater than 1.0 g/cm3.

Units of density ,mass and volume

• Kg/𝑚3 density of water =1000 Kg/𝑚3

• g/𝑐𝑚3 density of water =1g/𝑐𝑚3

1 kg= 1000g

1𝑚3=1000000𝑐𝑚3

𝑚3=1000L

𝑐𝑚3=0.001 L

Solve the following problem:

•A small block of wood has a volume of 25 cubic centimeters and a mass of 20 grams. What is the density of the wood? Will it float in water?

How to solve

• D = mass/volume

• Mass = 20 g

• Volume = 25 cm3

• ? = 20g/ 25 cm3

• Density = 0.8 g/cm3

• Will it float in water?

• Yes because the density is less than 1.o g/cm3

which is the density of water.

Solve the following problem class activity

• A rectangular block of copper metal weighs 1.896 kg. The dimensions of the block are 8.4 cm by 5.5 cm by 4.6 cm. From this data, what is the density of copper?

How to solve

• D = m/v

• Mass = 1.896 kg = 1896 g

• Volume = l x w x h = 8.4 x 5.5 x 4.6 = 212.52 cm3

• D = 1896 g/ 212.52 cm3

• D = 8.92 g/cm3

Newton's Second Law

• Newton's Second Law of Motion states, “The force acting on an object is equal to the mass of that object times its acceleration.”

Example

Homework

Next Lecture

• Types of fluid

• Viscosity

References

• STREETER, V. Fluid Mechanics. By H. C. LOWE. Macmillan, 1979. 227 pp. 23.95. Fluid Mechanics. By J. F. DOUGLAS, JM GASIOREK and J. A. SWAPFIELD. Pit.

• Bansal, R. K. (2005). A textbook of fluid mechanics. Firewall Media.

• https://www.youtube.com/watch?v=7xw7Wvr-zq4