Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Heat Engines

Heat Engines

A heat engine is a device used to extract heat from a source and then convert it into mechanical work used for various applications. For example, a steam engine on an old-style train can produce the work needed for driving the train.
Whenever we consider heat engines (and associated devices such as refrigerators and heat pumps), we do not use the standard sign convention for heat and work. For convenience, we assume that the symbols Qh, Qc, and W represent only the amounts of heat transferred...

The Carnot Cycle

The Carnot Cycle

Converting work to heat is an irreversible process, and the purpose of a heat engine is to reverse the effect partially. Heat engines aim to increase the efficiency of the reversal, that is, maximize the work retrieved from heat. If the efficiency of a heat engine were 100%, it would imply reversing the process completely without introducing any other effect. Thus, it would violate the second law of thermodynamics.
What could be the theoretical limit to the efficiency of a heat engine? The...

Carnot Cycle and Efficiency

Carnot Cycle and Efficiency

The Second Law of Thermodynamics asserts that it's impossible for any heat engine to achieve 100% efficiency. While contemplating the maximum possible efficiency, Nicolas Sadi Carnot conceptualized an ideal heat engine. This engine gets its energy from a high-temperature reservoir. It then performs some work and releases the remaining energy into a low-temperature reservoir.The Carnot cycle, named after Sadi Carnot, is fully reversible. The cycle consists of four distinct stages. In the first...

The Carnot Cycle and the Second Law of Thermodynamics

The Carnot Cycle and the Second Law of Thermodynamics

The Carnot engine works between two heat reservoirs of fixed temperatures. The Carnot cycle begs the following question: Is it possible to devise a heat engine that is more efficient than a Carnot engine between two fixed temperatures? The answer lies in designing a Carnot refrigerator.
Since the individual steps in a Carnot cycle can be reversed, the entire cycle is, thus, reversible. If a Carnot cycle is reversed, it becomes a Carnot refrigerator. It extracts heat Qc from a cold reservoir at...

Efficiency of The Carnot Cycle

Efficiency of The Carnot Cycle

The hypothetical Carnot cycle consists of an ideal gas subjected to two isothermal and two adiabatic processes. Since the internal energy of an ideal gas depends only on its temperature, which is the same before and after the completion of the Carnot cycle, there is no change in its internal energy. Hence, using the first law of thermodynamics, the total heat exchanged by the ideal gas equals the total work done. Thus, we can quantify the efficiency of the Carnot cycle via the heat exchanged...

Statements of the Second Law of Thermodynamics

Statements of the Second Law of Thermodynamics

The second law of thermodynamics can be stated in several different ways, and all of them can be shown to imply the others. The Clausius’ statement of the second law of thermodynamics is based on the irreversibility of spontaneous heat flow. It states that heat will not flow from the colder body to the hotter body unless some other process is involved. Additionally, as per the Kelvin’s statement, it is impossible to convert the heat from a single source into work without any other effect. This...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Quantum versus Classical Thermal Transport at Low Temperatures.

Physical review letters·2026

Same author

Local integrability breaking and exponential localization of leading Lyapunov vectors.

Physical review. E·2025

Same author

Photonic Eigenmodes of 2D Cylindrical Cholesteric Liquid Crystal Resonators.

ACS photonics·2025

Same author

Efficient Computation of Cumulant Evolution and Full Counting Statistics: Application to Infinite Temperature Quantum Spin Chains.

Physical review letters·2025

Same author

Exact Nonequilibrium Steady State of XXZ Circuits Boundary Driven with Arbitrary Resets or Fields.

Physical review letters·2025

Same author

Full Eigenstate Thermalization via Free Cumulants in Quantum Lattice Systems.

Physical review letters·2025

Search research articles

Related Experiment Video

Updated: Jun 21, 2026

Asymmetric Thermoelectrochemical Cell for Harvesting Low-grade Heat under Isothermal Operation

Asymmetric Thermoelectrochemical Cell for Harvesting Low-grade Heat under Isothermal Operation

Published on: February 5, 2020

Exactly solvable model of a highly efficient thermoelectric engine.

Martin Horvat¹, Tomaz Prosen, Giulio Casati

¹Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana, Slovenia. martin.horvat@fmf.uni-lj.si

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics

|August 8, 2009

Summary

A new classical dynamical model demonstrates a thermoelectric heat engine can achieve Carnot efficiency. By adjusting parameters in unequal scattering channels, optimal performance is possible.

More Related Videos

A Rapid Method for Modeling a Variable Cycle Engine

A Rapid Method for Modeling a Variable Cycle Engine

Published on: August 13, 2019

Related Experiment Videos

Last Updated: Jun 21, 2026

Asymmetric Thermoelectrochemical Cell for Harvesting Low-grade Heat under Isothermal Operation

Asymmetric Thermoelectrochemical Cell for Harvesting Low-grade Heat under Isothermal Operation

Published on: February 5, 2020

A Rapid Method for Modeling a Variable Cycle Engine

A Rapid Method for Modeling a Variable Cycle Engine

Published on: August 13, 2019

Area of Science:

Thermodynamics
Statistical Mechanics
Materials Science

Background:

Thermoelectric and thermochemical heat engines are crucial for energy conversion.
Achieving maximum theoretical efficiency (Carnot efficiency) is a key goal in engine design.
Classical dynamical models offer a simplified yet insightful approach to understanding engine performance.

Purpose of the Study:

To propose and analyze a simple classical dynamical model for a thermoelectric or thermochemical heat engine.
To investigate the operational characteristics and efficiency limits of such an engine.
To determine if Carnot's efficiency can be reached under specific conditions.

Main Methods:

Development of a classical dynamical model involving two ideal gas containers.
Connection of the containers via two unequal scattering channels.
Analytical solution of the model to derive performance characteristics.
Parameter optimization to identify conditions for maximum efficiency.

Main Results:

The proposed model is analytically solvable.
A specific combination of model parameters allows the engine to operate at Carnot's efficiency.
The unequal scattering channels play a critical role in achieving optimal performance.

Conclusions:

A simple classical dynamical model can effectively represent a thermoelectric/thermochemical heat engine.
Carnot efficiency is attainable in this model through careful parameter selection.
This work provides theoretical insights into the design of high-efficiency heat engines.