Explore Nonequilibrium Thermodynamics with interactive simulations. Understand entropy production, fluxes, forces, and the dynamics of systems far from equilibrium.
Nonequilibrium thermodynamics is a branch of thermodynamics that deals with systems that are not in thermodynamic equilibrium. Unlike classical thermodynamics, which focuses on equilibrium states, nonequilibrium thermodynamics studies the dynamics of systems with gradients in temperature, pressure, concentration, or other intensive properties.
The field provides a framework for understanding how systems evolve toward equilibrium and how they behave when maintained in nonequilibrium steady states by external constraints. Central to this field are concepts like entropy production, fluxes and forces, and the Onsager reciprocal relations.
Nonequilibrium thermodynamics has wide-ranging applications in biology, chemistry, materials science, and engineering, particularly in understanding transport processes, chemical reactions, and pattern formation in complex systems.
Understanding irreversible processes and entropy generation
Select a process type to see its entropy production characteristics.
Linear and nonlinear relationships in nonequilibrium systems
In nonequilibrium thermodynamics, fluxes (J) are driven by thermodynamic forces (X) through relationships of the form:
J = L × X
Where:
J = Flux (flow of matter, energy, etc.)
X = Thermodynamic Force (gradient)
L = Kinetic Coefficient (conductance)
Symmetry in coupled transport processes
For coupled processes near equilibrium:
J₁ = L₁₁X₁ + L₁₂X₂
J₂ = L₂₁X₁ + L₂₂X₂
Reciprocal Relation:
L₁₂ = L₂₁
Seebeck and Peltier effects demonstrate Onsager reciprocity:
Nonequilibrium thermodynamics in everyday life and research
Living organisms operate far from equilibrium, maintaining complex structures through continuous energy dissipation.
Understanding nonequilibrium processes is crucial for designing efficient systems and novel materials.
Earth's climate system operates far from equilibrium, driven by solar radiation and atmospheric dynamics.
Modern electronics rely on nonequilibrium processes for functionality and performance.
Vehicle engines and propulsion systems are classic examples of nonequilibrium thermodynamics.