DMT 11 - 20

Question 1

What are the 6 limitations of BE?

4 - 6

Answer 1

Ignoring Heat Transfer
Flow along a streamline
No shaft work

Question 2

Describe the limitations of: Steady Flow?

Answer 2

Can not be used during the transient start-up and shut-down periods, or during periods of change in the flow condition

Question 3

Describe the limitations of: Frictionless Flow?

Answer 3

Frictional effects are negligible for short flow sections with large cross sections, especially at low flow velocities

Question 4

Describe the limitations of: Incompressible Flow?

Answer 4

Can not be used when the density of it is changing

Question 5

Describe the limitations of: Ignoring Heat Transfer?

Answer 5

Since the density of a gas is inversely proportional to temperature

Question 6

Describe the limitations of: Flow along a streamline?

Answer 6

Ignoring any vorticities

Question 7

Describe the limitations of: No shaft work?

Answer 7

BE is not applicable in a flow section that involves a pump, turbine, fan, or any other machine or impeller since such devices destroy the streamline

Question 8

In reality, what are the assumptions on friction?

2

Answer 8

Shear stress in fluid and with pipe

Sheer stress work against flow

Question 9

What is BE if we take friction into consideration?

Answer 9

𝑃_1+(𝜌〖𝑣_1〗^2)/2+𝜌𝑔𝑧_1=

𝑃_2+(𝜌〖𝑣_2〗^2)/2+𝑝𝑔𝑧_2+∆𝑃

Question 10

What is ∆𝑃 representing?

Answer 10

Pressure Drop