Fundamentals of Fluid Flow

Question 1

Amount of fluid passing through a section per unit of time

Answer 1

Discharge/Flow Rate

Question 2

Formula of Volume Flow Rate

Answer 2

Q = Av

Question 3

Formula of Mass Flow Rate

Answer 3

Mf = pQ

Question 4

Formula of Weight Flow Rate

Answer 4

W = yQ

Question 5

Q is

Answer 5

discharge

Question 6

A is

Answer 6

cross-sectional area of flow

Question 7

v is

Answer 7

mean velocity of flow

Question 8

p is

Answer 8

mass density

Question 9

y is

Answer 9

unit weight

Question 10

Occurs when the discharge Q passing a given cross-section is constant with time

Answer 10

Steady Flow

Question 11

If the flow Q at the cross-section varies with time

Answer 11

Unsteady Flow

Question 12

Occurs if, with steady flow for a given length, the average velocity of flow is the same at every cross-section

Answer 12

Uniform Flow

Question 13

If the average velocity of flow varies at every cross-section

Answer 13

Non-uniform Flow

Question 14

Occurs when at any time, the discharge Q at every section of the stream is the same

Answer 14

Continuous Flow

Question 15

Formula of Continuous Flow for Incompressible Fluids

Answer 15

Q = A1v1 = A2v2 = A3v3 = constant

Question 16

Formula of Continuous Flow for Compressible Fluids

Answer 16

Q = p1A1v1 = p2A2v2 = p3A3v3 = constant

Question 17

When the path of individual fluid particles do not cross or intersect

Answer 17

Laminar Flow

Question 18

Occurs when the Reynolds number Re is less than (approximately) 2100

Answer 18

Laminar Flow

Question 19

When the path of individual particles are irregular and continuously cross each other

Answer 19

Turbulent Flow

Question 20

Occurs when the Reynolds number exceeds 2100 (most common situation is when it exceeds 4000)

Answer 20

Turbulent Flow

Question 21

The energy possessed by a flowing fluid

Answer 21

kinetic and potential energy

Question 22

Potential energy may be subdivided into

Answer 22

energy due to position or elevation above a given datum and energy due to pressure in the fluid

Question 23

The ability of the fluid mass to do work by virtue of its velocity

Answer 23

Kinetic energy

Question 24

Amount of energy per pound or Newton of fluid

Answer 24

Head

Question 25

Formula of Kinetic Energy

Answer 25

KE = ½mv² = ½(W/g)v²

Question 26

Formula of Kinetic Head or Velocity Head

Answer 26

Hv = v²/2g

Question 27

Formula of Potential Energy for Elevation

Answer 27

PE = mgh = Wh = Wz

Question 28

Formula of Elevation Head

Answer 28

Hz = z

Question 29

Formula of Potential Energy for Pressure

Answer 29

PE = mgh = W(p/y)

Question 30

Formula of Pressure Head

Answer 30

Hp = p/y

Question 31

Formula of Total Energy/Total Head

Answer 31

E = v²/2g + p/y + z

Question 32

Results from the application of the principles of conservation of energy

Answer 32

Bernoulli's Energy Theorem

Question 33

Bernoulli's Energy Theorem

Answer 33

E1 + Eadded - Eextracted = E2

Question 34

Energy Equation w/out Head Lost

Answer 34

E1 = E2 v1²/2g + P1/y + z1 = v2²/2g + P2/y + z2

Question 35

Energy Equation w/ Head Lost

Answer 35

E1 - HL = E2 v1²/2g + P1/y + z1 - HL = v2²/2g + P2/y + z2

Question 36

Energy Equation w/ Pump

Answer 36

E1 + HA - HL = E2

Question 37

Energy Equation w/ Turbine

Answer 37

E1 - HE - HL = E2

Question 38

Also known as pressure gradient

Answer 38

Hydraulic Grade Line

Question 39

The graphical representation of the total potential energy of flow

Answer 39

Hydraulic Grade Line

Question 40

A graphical representation of the total energy of flow

Answer 40

Energy Grade Line

Question 41

The rate at which work is done

Answer 41

Power

Question 42

Formula of Power

Answer 42

P = yQE

Question 43

1 hp in Watts and ft-lb/sec

Answer 43

746 Watts 550 ft-lb/sec

Question 44

1 Watt in N-m/s and J/s

Answer 44

1 N-m/s 1 J/s

Question 45

Formula of Power for Pump

Answer 45

Poutput = yQ(HA)

Question 46

Formula of Efficiency for Pump

Answer 46

Effpump = Poutput/Pinput x 100%

Question 47

Formula of Power for Turbine

Answer 47

Pinput = yQ(HE)

Question 48

Formula of Efficiency for Turbine

Answer 48

Effpump = Poutput/Pinput x 100%

Question 49

The input power of the pump is the ___ and its output power is ____.

Answer 49

electrical energy, flow energy

Question 50

The ratio of the inertia force to viscous force

Answer 50

Reynolds Number

Question 51

Formula of Reynolds Number

Answer 51

Re = vDρ/μ