Mechanical Engineering - Fluid Mechanics Important Question And Answer

1).What is fluid mechanic’s?

A) fluid mechanics is the application of the laws of force and motion to fluids, i.e. liquids and gases. There are two branches of fluid mechanics:

1)fluid statics and,

2)fluid dynamics. 

 

2).define fluid statics and fluid dynamics?

A) Fluid Statics:  is the study of fluids at rest. The main equation required for this is. Newton's second law for nonaccelerating bodies.

Fluid dynamics: is the study of fluids in motion. The main equation required for this is Newton's second law for accelerating bodies.

3). What Is Cavitation?

A) Cavitation is the formation of vapor cavities (Air bubbles) in a liquid.

4) . How Cavitation Can Be Eliminated In A Pump?

A) Cavitation means bubbles are forming in the liquid.

• To avoid Cavitation, we have to increase the Pump size to One or Two Inch;
• To increase the pressure of the Suction Head, or
• Decrease the Pump Speed.

5). Which Pump Is More Efficient Centrifugal Pump Or Reciprocating Pump?

A) 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.

6). Why Centrifugal Pump Is Not Called As A Positive Displacement Type Of Pump?

A) The centrifugal has varying flow depending on pressure or head, whereas the Positive Displacement pump has more or less constant flow regardless of pressure.

7). Why The Centrifugal Pump Is Called High Discharge Pump?

A) Centrifugal pump is a kinetic device. The centrifugal pump uses the centrifugal force to push out the fluid. So the liquid entering the pump receives kinetic energy from the rotating impeller. The centrifugal action of the impeller accelerates the liquid to a high velocity, transferring mechanical (rotational) energy to the liquid. So it discharges the liquid in high rate. 

8). What Is A Radial flow Turbine?

A) In a radial flow turbine, steam flows outward from the shaft to the casing. The unit is usually a reaction unit, having both fixed and moving blades.

9). What Are Two Types Of Clearance In A Turbine?

A). 1) Radial – clearance at the tips of the rotor and casing.

2) Axial – the foreandaft

clearance, at the sides of the rotor and the casing.

10). What Is A Stage In A Steam Turbine?

A) In an impulse turbine, the stage is a set of moving blades behind the nozzle. In a reaction turbine, each row of blades is called a "stage." A single Curtis stage may consist of two or more rows of moving blades.