GATE MECHANICAL NOTES

  The Brayton Cycle: An In-depth Exploration Introduction The Brayton cycle, named after George Brayton, is a thermodynamic cycle that describes the workings of a constant-pressure heat engine. The cycle is the fundamental principle behind modern jet engines and gas turbine engines, making it a cornerstone of both aviation and power generation industries. This blog will explore the Brayton cycle in detail, covering its history, theoretical derivation, practical applications, and recent advancements. Historical Background The Brayton cycle was first proposed by George Brayton in the 19th century. Initially, it was used for piston engines but later adapted for gas turbines. Brayton's work laid the foundation for the development of efficient and powerful engines, significantly impacting aviation and energy sectors. Basic Concepts Thermodynamic Cycles Thermodynamic cycles are processes that involve the transfer of heat and work into and out of a system, resulting in the system returnin...

  Derivation of the Steady Flow Energy Equation (SFEE) The Steady Flow Energy Equation (SFEE) is an important concept in thermodynamics, particularly for analyzing the performance of various engineering systems like turbines, compressors, heat exchangers, and nozzles. The SFEE is derived from the first law of thermodynamics applied to a control volume under steady-state conditions. In this blog, we will go through a highly detailed derivation of the SFEE step by step. Steady Flow System and Control Volume Consider a control volume where fluid enters and exits at steady state. Steady state implies that the properties of the fluid within the control volume do not change with time. This means: The mass flow rate is constant. The energy of the system is constant over time. Let’s define the variables: m ˙ \dot{m} m ˙ : Mass flow rate (kg/s) Q ˙ \dot{Q} Q ˙ ​ : Rate of heat transfer into the system (W or J/s) W ˙ \dot{W} W ˙ : Rate of work done by the system (W or J/s) h h h : Specific e...

  Why the Ideal Carnot Cycle is Not Possible: Real-World Limitations and Processes The Carnot cycle is an idealized thermodynamic cycle that represents the maximum possible efficiency a heat engine can achieve when operating between two thermal reservoirs. However, in the real world, achieving an ideal Carnot cycle is not possible due to several inherent limitations. These limitations arise from the nature of the processes involved in the cycle and the physical properties of materials and systems. In this blog, we will explore why the ideal Carnot cycle is not achievable and identify the processes that contribute to this impossibility. Understanding the Carnot Cycle The Carnot cycle consists of four reversible processes: Isothermal Expansion at high temperature ( T H T_H T H ​ ). Adiabatic Expansion from high temperature ( T H T_H T H ​ ) to low temperature ( T C T_C T C ​ ). Isothermal Compression at low temperature ( T C T_C T C ​ ). Adiabatic Compression from low temperature...