LABS - 4A: Energy Loss in Bends

Question 1

What does Bernoulli’s principle state?

Answer 1

As the speed of a moving fluid increases, the pressure exerted by that fluid decreases.
(Pressure is inversely proportional to fluid velocity).

Question 2

What is the equation for Bernoulli’s principle?

Answer 2

p + (ρv²)/2 + ρgh = constant

Where:
p = pressure
ρ = density
v = velocity
h = height/elevation
g = acceleration by gravity

[dynamic and static pressures]

Question 3

What kind of energy losses does a fluid experience in pipework?

Answer 3

Ek transferred and lost as heat energy (due to friction/head loss due to friction)

Question 4

What’s head loss?

Answer 4

Energy lost due to resistance to flow.

This can occur due to sudden changes e.g. in pipe diameter

Major loss - loss in pipes and ducts
Minor loss - loss in components e.g. valves

Question 5

What is the loss coefficient, K l?

Answer 5

A ratio of potential to kinetic energies, suggesting any additional energy lost in flow.

Question 6

What do manometers measure?

Answer 6

Pressure

Question 7

What factors affect energy losses in pipes?

Answer 7

Fluid flow velocity
Length of pipe
Width/diameter of pipe
Pipe material (resulting in friction)
Change in direction of fluid flow
Obstacles or obstructions within the pipes
Type of fluid flow (e.g. laminar or turbulent)