Answer Posted / bn
when the local pressure in a liquid falls below the vapour
pressure, for that temperature, the liquid boils locally
and forms bubbles; this is flashing.
If the pressure subsequently increases, the bubbles colapse
violently; this is cavitation.
If the liquid contains dissolved gases, when the local
pressure is reduced gas bubbles will form before the liquid
starts to boil.
If the pressure is subsequently increased, the gas bubbles
will colapse but much slower than the colapse of a vapour
bubble. This is pseudo-cavitation.
It is the colapse of vapour bubbles which causes noise,
vibration and local damage. Pseudo-cavitation may not do
much damage to rotodynamic pumps. Pseudo-cavitation will
destroy some pd pumps just like cavitation. Pump operating
conditions, pumped liquid and pump design are critical
factors.
| Is This Answer Correct ? | 7 Yes | 0 No |
Post New Answer View All Answers
Why do you need a keyway in the construction of a wall?
Is OHNS steel is equivalent to O1 tool steel? Suppliers give OHNS material for AISI O1 STEEL telling that both are equivalent materials. Is this correct?
thermal engineering
What is the unit of viscosity?
When maximum discharge is obtained in nozzle ?
Define the terms free energy and free enthalpy. What is their significance and importance ?
Dear friends, i am a student of mechanical final year in rajasthan. If you have any type (Technical,interview, aptitude) of question paper related to BIRLA CEMENT LTD. than plz send me these paper at vinodsainikumar4@gmail.com thanks
List the different devices and components of main switchboard.
What do you mean by A.CC.?
why oil lift in screw chiller during change of climate.
What is the role of nitrogen in welding?
Fabrication Defects
How to report calorific values of fuel?
What is the difference between upstream and downstream in a refinery?
how to measure static charge in processing of expandable polystyrene. explain - Units of static charge