Carnot Cycle: Understanding Why Real Engines Fall Short

In summary, the Carnot Cycle is a theoretical thermodynamic cycle that sets the limit for the maximum efficiency of engines converting heat into work. It differs from real engine cycles due to assumptions of reversibility and no energy losses. The four processes involved are isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression. The Carnot Cycle relates to the Second Law of Thermodynamics by demonstrating the maximum efficiency that can be achieved. Understanding the Carnot Cycle has practical significance for engineers and scientists in determining theoretical efficiency, optimizing real engines, and evaluating their performance.
  • #1
drcrabs
47
0
Why do real engines never attain the efficiency of the Carnot cycle?
 
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  • #2
Two reasons:
-First, they don't use the carnot cycle because its acts slowly.
-Second, all real engines produce friction and other losses.
 
  • #3
So what type are processes are we talking about?
 
  • #4
Carnot cycle: reversible processes require infinite time to complete.

"Real engine:" processes are completed in finite time, and are, therefore, irreversible, meaning more heat is lost in increasing the entropy of the universe.
 
  • #5

What is the Carnot Cycle and why is it important in understanding real engines?

The Carnot Cycle is a theoretical thermodynamic cycle that describes the most efficient way to convert heat into work. It is important in understanding real engines because it sets a limit on the maximum efficiency that can be achieved by any engine operating between two temperatures.

How does the Carnot Cycle differ from real engine cycles?

The Carnot Cycle is a theoretical cycle that assumes all processes are reversible and that there are no energy losses, while real engines operate on cycles with irreversible processes and energy losses due to friction and other factors. This means that real engines will always fall short of the efficiency predicted by the Carnot Cycle.

What are the four processes involved in the Carnot Cycle?

The four processes involved in the Carnot Cycle are isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression. These processes involve the transfer of heat and work to and from the engine, resulting in a net conversion of heat into work.

How does the Carnot Cycle relate to the Second Law of Thermodynamics?

The Carnot Cycle is closely related to the Second Law of Thermodynamics, which states that it is impossible to convert heat completely into work without any losses. The Carnot Cycle demonstrates the maximum efficiency that can be achieved when converting heat into work, and any real engine will always have lower efficiency due to the Second Law.

What is the practical significance of understanding the Carnot Cycle for engineers and scientists?

Understanding the Carnot Cycle allows engineers and scientists to determine the maximum theoretical efficiency of engines and other systems that convert heat into work. It also helps in the design and optimization of real engines by identifying areas where energy losses can be reduced. Additionally, the Carnot Cycle serves as a benchmark for evaluating the performance of real engines.

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