20 Gas Turbine Interview Questions and Answers

Gas turbines are a type of internal combustion engine that are used in a variety of applications. They are commonly used in power generation, but can also be used in aircraft, ships, and land-based vehicles. When interviewing for a position that will involve working with gas turbines, it is important to be prepared to answer questions about your experience and qualifications. In this article, we review some common gas turbine interview questions and provide tips on how to answer them.

Gas Turbine Interview Questions and Answers

Here are 20 commonly asked Gas Turbine interview questions and answers to prepare you for your interview:

1. What is a gas turbine?

A gas turbine is a type of internal combustion engine that converts the energy in a gas into mechanical energy. This energy can then be used to power an aircraft, a generator, or a pump.

2. Can you explain the working principle of a gas turbine engine?

Gas turbine engines work by compressing air and then mixing it with fuel that is combusted. This hot gas expands through a turbine, which powers the engine. The exhaust from the turbine is then used to power a second stage, which helps to increase the overall efficiency of the engine.

3. How does friction affect the performance of a gas turbine engine?

Friction creates drag and resistance within the engine, which can lead to a loss of power and efficiency. In order to minimize the effects of friction, gas turbine engines are designed with precision tolerances and smooth surfaces.

4. Can you name some common applications of a gas turbine?

Gas turbines are commonly used in power generation, aircraft propulsion, and as a mechanical drive in industrial settings.

5. Is it possible to use a gas turbine in an automobile or aircraft?

Yes, it is possible to use a gas turbine in an automobile or aircraft. Gas turbines are often used in jet engines, which power both commercial and military aircraft. Gas turbines can also be used in land-based vehicles, such as trains and cars.

6. What are the main components of a gas turbine engine?

The main components of a gas turbine engine are the compressor, the combustion chamber, and the turbine. The compressor draws in air and compresses it, the combustion chamber ignites the fuel and air mixture, and the turbine extracts energy from the expanding gases to power the compressor.

7. What do you understand by compressor efficiency?

Compressor efficiency is a measure of how well a compressor is able to compress the air that it is taking in. The higher the compressor efficiency, the less work the compressor has to do to compress the air, and the lower the energy consumption of the compressor.

8. What’s the difference between a centrifugal and axial flow compressor?

The main difference between centrifugal and axial flow compressors is the direction of air flow. In a centrifugal compressor, air flows perpendicular to the axis of rotation, while in an axial flow compressor, air flows parallel to the axis of rotation. Centrifugal compressors are typically more efficient than axial flow compressors, but axial flow compressors are more compact and can handle higher airflow rates.

9. What is the purpose of a regenerator in a gas turbine setup?

The purpose of a regenerator is to help improve the efficiency of the gas turbine by pre-heating the air that is being drawn into the turbine. The regenerator does this by using the heat that is being generated by the turbine itself, which would otherwise be wasted. By pre-heating the air, the turbine can work more efficiently and produce more power.

10. What is meant by air standard cycle?

The air standard cycle is a theoretical cycle that models the ideal performance of a gas turbine engine. The air standard cycle is used to compare the performance of different gas turbine engines and to determine the efficiency of the engine under different operating conditions.

11. What are the different types of Brayton cycles?

The four different types of Brayton cycles are the ideal cycle, the real cycle, the regenerative cycle, and the reheat cycle.

12. What is the purpose of a diffuser in a gas turbine engine?

The diffuser is responsible for slowing down the airflow that has been accelerated by the compressor. This is necessary in order for the air to be properly mixed with fuel in the combustion chamber.

13. Why is there no compression process in a Diesel cycle?

The Diesel cycle is a compression-ignition engine, meaning that the fuel is ignited by the heat of compression rather than by a spark. In a Diesel engine, the air is compressed first, and then fuel is injected into the cylinder. The heat of the compressed air ignites the fuel, and the expanding gases drive the piston down.

14. What is the usage of the combustion chamber in a gas turbine engine?

The combustion chamber is where the fuel and air are mixed and burned in order to create the hot gases that will power the engine.

15. What are the different types of combustion chambers used in a gas turbine engine?

The three main types of combustion chambers used in gas turbine engines are the can-type, the annular, and the can-annular. The can-type combustion chamber is the simplest and most common type, consisting of a cylindrical chamber with a fuel injector at the bottom. The annular combustion chamber is more complex, consisting of an inner and outer ring with a fuel injector in the middle. The can-annular combustion chamber is the most complex, consisting of a can-type chamber inside of an annular chamber.

16. What is the purpose of a nozzle in a gas turbine engine?

The nozzle in a gas turbine engine is responsible for converting the thermal energy of the hot gases into kinetic energy. This increases the velocity of the gases as they exit the engine, which in turn increases the thrust that the engine produces.

17. What is the significance of anti-icing devices on aircraft turbines?

Anti-icing devices are used on aircraft turbines to prevent ice buildup on the blades. Ice buildup can cause the blades to become unbalanced and can lead to engine failure. The use of anti-icing devices helps to ensure that the blades remain free of ice and can continue to function properly.

18. What are the differences between turbojet, turboprop, and turbofan engines?

Turbojet engines are the simplest type of gas turbine engine, and they work by compressing air and then mixing it with fuel that is burned in order to create thrust. Turboprop engines are similar to turbojet engines, but they have a propeller that is driven by the turbine in order to create thrust. Turbofan engines are the most common type of gas turbine engine, and they work by compressing air and then mixing it with fuel that is burned in order to create thrust. The exhaust from the engine then drives a fan that helps to create additional thrust.

19. What is the role of a turbine in a gas turbine engine?

The turbine in a gas turbine engine is responsible for providing the energy to drive the compressor. The turbine is powered by the hot gases that are produced by the combustion process. The gases flow through the turbine blades, which spin the turbine. The turbine is connected to the compressor by a shaft, and the energy from the turbine is used to drive the compressor.

20. What are the advantages of using gas turbines over steam turbines?

Gas turbines have a number of advantages over steam turbines. They are more efficient, they can be started up more quickly, and they can operate at a wider range of speeds. Additionally, gas turbines can run on a variety of different fuels, including natural gas, propane, and even jet fuel.