Lectures 7-8

Question 1

Equation for the n-component of acceleration of a particle in a fluid, a n =

Answer 1

a n = V^2 / R

normal component of acceleration = velocity^2 / radius of curvature of streamline

Question 2

Euler’s equation along a streamline

Answer 2

(dp / ds) + (ρg ( dz / ds )) + (ρV ( dV / ds )) = 0

Question 3

Bernoulli’s equation is

Answer 3

p + ρ g z + 1/2 ρ V^2

Question 4

Jet velocity:

Answer 4

V2 = √ (2 ρ g h / ρ ) = √ (2 g h )

Question 5

Vena contracta in latin means

Answer 5

contracted vein

Question 6

Vena contracta is

Answer 6

the amount by which a fluid contracts as it flows out of a container through a nozzle

Question 7

Vena contracta equation is

Answer 7

it is a ratio of the actual flow rate / theoretical flow rate

Question 8

When using Bernoulli’s equation on a container to calculate the flow characteristics and volume change, what is important to remember about the first reference point?

Answer 8

That it is somewhere with easy values of static and elevation pressures and velocity

Question 9

Vena contraction ratio can also be known as

Answer 9

contraction coefficient

Question 10

Three other effects where the use of Bernoulli’s equation is limited to

Answer 10

• No frictional effects, no stresses, no energy losses
• No shaft work - no pumps or turbines

Question 11

What is the limitation on the use of Bernoulli’s equation when the compressibility effects are mentioned?

Answer 11

• Density is constant for liquids and gases at low speed
• High speed gas flow must include effects of density change