pipes and pumps Flashcards
1
Q
what can happen if flow changes direction too rapidly?
A
regions of separated flow generated, where eddies form, enhance losses
2
Q
what is the difference between pipes in series and pipes in parallel?
A
- series: flow rate the same
- parallel: pressure loss the same
3
Q
what does a pump do?
A
converts shaft work into fluid KE
4
Q
what does a turbine do?
A
converts fluid KE to shaft work
5
Q
what is the BEP?
A
- best efficiency point
- point where optimum design is
6
Q
describe cavitation
A
- boiling points of liquids depend on pressure
- if the pressure drops below a certain value, boiling occurs
- boiling causes formation of vapor bubbles (cavitation)
- bubbles reduce performance due to combined density of fluid and bubbles and damage the pumps
7
Q
what is NPSH?
A
- net positive suction head
- minimum inlet head to prevent cavitation
8
Q
when do we use pumps in series?
A
when one pump does not provide sufficient head
9
Q
when do we use pumps in parallel?
A
when a single pump does not provide sufficient discharge
