Sunday, May 28, 2023

10 Common Applied Thermodynamics Questions Asked in The Interviews: Theory Series 02

 

1.     What is the Brayton cycle? 
Answer: The Brayton cycle is a thermodynamic cycle that describes the operation of gas turbine engines. It consists of four processes: isentropic compression, constant pressure heat addition, isentropic expansion, and constant pressure heat rejection. The Brayton cycle is commonly used in gas turbine power plants and jet engines.
 
2.     What is the Otto cycle? 
Answer: The Otto cycle is a thermodynamic cycle that represents the operation of spark-ignition internal combustion engines, commonly used in automobiles. It consists of four processes: isentropic compression, constant volume heat addition, isentropic expansion, and constant volume heat rejection.
 
3.     Explain the concept of air-fuel ratio in combustion. 
Answer: The air-fuel ratio represents the ratio of the mass of air to the mass of fuel in a combustion process. It is a crucial parameter that influences the efficiency and performance of combustion systems. The stoichiometric air-fuel ratio is the ideal ratio at which complete combustion occurs, ensuring efficient utilization of fuel.
 
4.     What is a Rankine cycle? 
Answer: The Rankine cycle is a thermodynamic cycle that represents the operation of steam power plants. It consists of four processes: isentropic compression, constant pressure heat addition, isentropic expansion, and constant pressure heat rejection. The Rankine cycle is commonly used in steam power generation systems.
 
5.     Define specific volume and its importance in thermodynamics.
 Answer: Specific volume (v) is the volume occupied by a unit mass of a substance. It is the reciprocal of density and provides insights into the spacing between molecules or particles. Specific volume is an important property in thermodynamics as it influences the behavior and performance of substances during processes such as compression, expansion, and heat transfer.
 
6.     What is a regenerative cycle in thermodynamics?
Answer: A regenerative cycle is a thermodynamic cycle that utilizes the extraction of heat from the working fluid leaving the cycle to preheat the fluid entering the cycle. It improves the overall efficiency of the cycle by reducing the amount of heat required from external sources. The regenerative cycle is commonly used in steam power plants.
 
7.     Explain the concept of a compressor in thermodynamics. 
Answer: In thermodynamics, a compressor is a device used to increase the pressure and temperature of a gas by reducing its volume. Compressors play a vital role in various applications such as gas turbines, refrigeration systems, and air conditioning systems. They are typically classified as positive displacement compressors or dynamic compressors.
 
8.     What is the purpose of a condenser in a refrigeration system? 
Answer: A condenser is a component in a refrigeration system that removes heat from the refrigerant gas and converts it into a liquid state. It facilitates the rejection of heat to the surroundings, allowing the refrigerant to release the absorbed heat and cool down. The condenser plays a crucial role in the heat rejection process of a refrigeration cycle.
 
9.     Define the coefficient of performance (COP) in refrigeration systems. 
Answer: The coefficient of performance (COP) is a measure of the efficiency of a refrigeration system. It represents the ratio of the heat extracted from the refrigerated space to the work input to the system. A higher COP indicates a more efficient refrigeration system.
 
10.  Explain the concept of irreversibility in thermodynamics. 
Answer: Irreversibility refers to the deviation from an ideal reversible process in a thermodynamic system. In practical systems, various irreversibilities such as friction, heat transfer across finite temperature differences, and pressure losses occur. Irreversibilities lead to inefficiencies and decrease the overall performance of thermodynamic processes.
 
You can read the author's book which might be beneficial to you.

No comments:

Post a Comment

If you have any doubts, let me know

Health is wealth for students

   (Photo source:pexels.com)   Nowadays, when I look around, most of the students are either obese or have some kind of health issues. ...