Q: How Cavitation can be eliminated in a Pump?
Ans.:
• Increase the Pump size to One or Two Inch,
• Increase the pressure of the Suction Head,
Q: One litre = ________cm3 .
Ans.: 1000 cm3 .
Q: Which Pump is more Efficient Centrifugal Pump or Reciprocating Pump?
Ans.: Centrifugal pump. Because flow rate is higher compared to reciprocating pump. Flow is smooth and it requires less space to install. Lower initial cost and lower maintenance cost.
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Ans.: Centrifugal pump. Because flow rate is higher compared to reciprocating pump. Flow is smooth and it requires less space to install. Lower initial cost and lower maintenance cost.
Q: One litre = ________cm3 .
Ans.: 1000 cm3 .
Q: What is cavitation?
Ans.: Cavitation is the formation of vapor cavities (Air bubbles) in a liquid.
Q: How Cavitation can be eliminated in a Pump?
Ans.:
• Increase the Pump size to One or Two Inch,
• Increase the pressure of the Suction Head,
• Decrease the Pump Speed.
Q: What is positive displacement pump?
Ans.: Positive displacement pumps are those that operate by forcing a fixed volume of fluid from the inlet pressure section of the pump into the discharge zone of the pump.
Q: What is kinematic viscosity?
Ans.: The kinematic viscosity is the ratio of absolute viscosity to the density of the liquid.
Q: Differentiate between the Uniform Flow and Non-Uniform Flow?
Ans.:
Uniform Flow: The flow is defined as uniform flow when in the flow field the velocity and other hydrodynamic parameters do not change from point to point at any instant of time.
Non-Uniform Flow: When the velocity and other hydrodynamic parameters changes from one point to another the flow is defined as non-uniform flow.
Q: What is the difference between the unsteady uniform flow and steady uniform flow?
Ans.:
Unsteady uniform flow - changes with time.
Steady uniform flow - does not change with time.
Q: Why Centrifugal Pump is not called as a Positive Displacement Type of Pump?
Ans.: The centrifugal has varying flow depending on pressure or head, whereas the Positive Displacement pump has more or less constant flow regardless of pressure.
Likewise viscosity is constant for positive displacement pump where centrifugal pump have up and down value because the higher viscosity liquids fill the clearances of the pump causing a higher volumetric efficiency. When there is a viscosity change in supply there is also greater loss in the system. This means change in pump flow affected by the pressure change.
One more example is, positive displacement pump has more or less constant efficiency, where centrifugal pump has varying efficiency rate.
SO Centrifugal Pump is not called as a Positive Displacement Type of Pump.
Q: What is Coefficient of contraction?
Ans.: Coefficient of contraction is the ratio of area of jet at vena contracta to the area of orifice.
The typical value may be taken as 0.64 for a sharp orifice (concentric with the flow channel). The smaller the value, the more effect the vena contracta has.
