Question Set 71

 

1.Why gas containers are mostly in a cylindrical shape?

The ideal shape would be a sphere. The container must have the capacity to withstand the extremely high pressure of liquefied gas. A spherical shape helps in distributing these forces uniformly.

2.Explain why re-heater is used in gas turbine

The advantage of reheater is that it significantly increases the thrust; which is a prime reason for its use in gas turbines.

3.How many types of suspensions are used in automobiles?

McPherson struts

Leaf spring

Coil spring

Torsion beam

Wishbone

Air Suspension

4.What is DTSI? Why it is used in motor bikes?

Digital Twin Spark Ignition. This is used for a better fuel combustion in the cylinder head which helps provide better efficiency and optimum use of fuel.

5.What are the advantages of DTSI over normal engines?

The cylinder head has two spark plugs, instead of the usual one. When two sparks are generated at either ends of the combustion chamber, the air-fuel mixture is ignited in a way that creates two flame fronts. A higher rate of combustion is achieved leading to higher rise in pressure. The outcome of this is more torque, better fuel efficiency and lower emissions.

6.What is meant by gear ratio?

A gear ratio is a direct measure of ratio of the rotational speeds of two or more interlocking gears.

7.What is the ratio of specific heat of air?

The ratio of specific heat γ=CP/CV is a factor in adiabatic engine processes and in determining the speed of sound in gas. This ratio γ=1.66 for an ideal monoatomic gas and γ=1.4 for air, which is predominantly a diatomic gas.

8.What is the percentage of carbon present in pig iron?

Carbon content is generally 3.5-4.5%.

 

 

9. Explain the second law of thermodynamics.

The entropy of the universe increases over time and moves towards a maximum value.

 

 

10. What kinds of pipes are used for steam lines?

Normally galvanized pipes are not used for steam. Mild steel with screwed or welded fittings are the norm. Pressure and temperature are very important factors to be considered in what type of materials to be used. Steam even at low pressures can be extremely dangerous.