Lesson 1: Introduction to Fluid Mechanics

Question 1

a science that deals with the behavior of fluids at rest or in motion, and the interaction of fluids with solids or other fluids at the boundaries

> science that deals with fluid behavior in motion at at rest, as well as its interaction with other fluids and boundaries

Answer 1

fluid mechanics

Question 2

3 characteristics of fluid

Answer 2

• liquid/gas
• deforms continuously under the influence of a shear stress
• stress is proportional to strain rate

Question 3

force per unit area

Answer 3

stress

Question 4

stress perpendicular to the surface

Answer 4

normal stress

Question 5

stress tangential component of the force

Answer 5

shear stress

Question 6

a fluid in direct contact with a solid “sticks” to the surface

Answer 6

no-slip condition

Question 7

flow region adjacent to the wall in which the viscous effects are significant

Answer 7

boundary layer

Question 8

flow over a curved surface

Answer 8

flow separation

Question 9

12 general classifications of fluid flow

Answer 9

1. viscous
2. inviscid
3. external
4. internal
5. compressible
6. incompressible
7. laminar
8. turbulent
9. natural
10. forced
11. steady
12. unsteady

Question 10

flow where frictional effects are significant

Answer 10

viscous flow

Question 11

flow where viscous forces are negligible

Answer 11

inviscid flow

Question 12

flow where there is unbounded fluid over a surface

Answer 12

external flow

Question 13

flow in a pipe or duct

Answer 13

internal flow

Question 14

flow where container is partially filled and there is a free surface (?)

Answer 14

open channel flow

Question 15

flow where density remains nearly constant throughout

Answer 15

incompressible flow (fluid?)

Question 16

flow that has highly ordered fluid motion characterized by smooth layers of fluid

Answer 16

laminar flow

Question 17

flow that is highly disordered fluid motion; typically occur at high velocities

Answer 17

turbulent flow

Question 18

flow that alternates between laminar and turbulent

Answer 18

transitional flow

Question 19

parameter used to determine if the flow is turbulent or laminar

Answer 19

Reynold’s number

Question 20

flow where fluid is forced to flow over a surface or in a pipe by external means such as pump

Answer 20

forced flow

Question 21

flow that occurs due to natural means such as buoyancy effect

Answer 21

natural flow

Question 22

flow that has no change of properties, velocity, temp at a point with time

Answer 22

steady flow

Question 23

flow that has no change with location over a specified region

Answer 23

uniform

Question 24

flow that is not steady

Answer 24

unsteady flow

Question 25

flow that is described as developing flows

Answer 25

transient flow

Question 26

kind of unsteady flow that oscillates about the steady mean

Answer 26

periodic flow

Question 27

quantity of a matter or a region in space chosen for study

Answer 27

system

Question 28

mass or region outside the system

Answer 28

surrounding

Question 29

separates the system from surrounding

Answer 29

boundary

Question 30

3 types of system

Answer 30

1. open (volume is controlled) 2. closed (mass is controlled) 3. isolated

Question 31

2 types of dimensions

Answer 31

1. primary/fundamental 2. secondary (derived)

Question 32

basic dimensions such as mass m, length L, temperature T

Answer 32

primary/fundamental dimensions

Question 33

expressed in terms of the primary dimensions

Answer 33

secondary dimensions

Question 34

the two sets of units in common use today

Answer 34

english and SI