Q1. Tell me about yourself.
Q2. Which is your favorite subject?
▶️My favorite subject is fluid flow.
Q3. What you studied in Fluid flow ?
▶️ I studied behavior of fluids and motion of fluids.
Q4. Assumptions of Bernoulli’s equation.
(i) the flow should be steady.
(ii) the flow should be irrotational.
(iii) the fluid should be ideal fluid.
Q5. What is cavitation?
▶️ Cavitation:
It happens in suction lift
Due to low pressure in suction pipe the boiling point of water decreases and it may start Boling at the temperature at which process is happening
Due to this vapors are formed and therefore there are bubbles in the impeller
When these bubbles collapse on the surface of pump, there is a jerk and this cause a cavity in the surface
When the bubbles collapse there is empty space
Liquid goes towards this empty space with large force
This causes shock waves and vibrations
Q6. What do you understand by priming ?
▶️Priming is a process of filling casing, delivery pipe with water to remove air to remove energy losses.
It is of two types,
(i).Positive priming :which speeds up the processing.
(ii) Negative priming: which slow downs the processing.
Q7. Is priming required for reciprocating pumps.
▶️No, priming is not required in reciprocating pumps as For Reciprocating pump, during suction phase, piston moves backward and form a low pressure zone in the pump. This pressure difference between suction & tank is large enough that it will pull the liquid, even if air pocket is present in the suction line. So we need not have priming operation. These are called self priming devices.
Q8.Define NPHS.
▶️NPSH is the minimum required pressure at the suction side of a pump. Low pressure at the suction side of the pump may reduce the efficiency of discharge pressure. In other words, cavitation,
If the suction pressure is only slightly greater than the vapor pressure, some liquid may flash to vapor inside the pump, we call it cavitation, which greatly reduces the pump capacity and causes severe erosion. If the suction pressure is actually less than the vapor pressure, there will be vaporization in the suction line, and no liquid can be drawn into the pump.
Therefore, to avoid cavitation, the pressure at the pump inlet must exceed the vapor pressure by a certain value which called the net positive suction head, NPSH.
Q9.Modes of heat transfer.
▶️There are 3 basic modes of transfer of heat:
1.Conduction:- it is transfer of heat in solids.
2.Convention:- it is transfer of heat in liquids- liquids and in gases -liquids
3.Radiation:- in this heat is transferred in the form of radiant wave and dose not require any medium for transfer.
Q10.Which mode of heat transfer is mostly used, give the example in which industry it is used .
Shell and tube type.
Shell and Tube , Petrochemical plant like polypropylenes, HDPE (High density polyethene), LLDPE( linear low density polyethene)