手法を比較

	フィックの法則	ブシネスク近似	シュテファン・マクスウェル拡散
分野	熱力学	熱力学	熱力学
系統	Process / pipeline	Process / pipeline	Process / pipeline
提唱年	1855	1903	1871
提唱者	Adolf Fick	Joseph Boussinesq	Josef Stefan and James Clerk Maxwell
種類	Diffusion law	Approximation technique	Diffusion equation
原典	Fick, A. (1855). On liquid diffusion. Philosophical Magazine, 10(63), 30-39.	Boussinesq, J. (1903). Théorie Analytique de la Chaleur. Gauthier-Villars.	Reid, R. C., Prausnitz, J. M., & Poling, B. E. (1987). The Properties of Gases and Liquids (4th ed.). McGraw-Hill. ISBN: 978-0071247009
別名	diffusion equation, Fickian diffusion	buoyancy approximation, Boussinesq model	Stefan-Maxwell equation, multicomponent diffusion
関連	3	3	3
概要	Fick's Laws describe how species diffuse through media due to concentration gradients. The First Law (steady-state) relates diffusion flux to concentration gradient, while the Second Law (transient) describes how concentration changes over time. These laws are fundamental to mass transfer analysis, applying to gases, liquids, and solids. Fick's Laws are analogous to Fourier's Law of heat conduction, replacing temperature with concentration.	The Boussinesq Approximation simplifies the governing equations for natural convection by treating density as constant except in the buoyancy term. This approximation is valid when temperature variations produce small density changes and allows researchers to solve coupled heat-fluid flow problems without solving the full, nonlinear compressibility equations. The Boussinesq Approximation is fundamental to analyzing buoyancy-driven flows in buildings, enclosures, and geophysical applications.	The Stefan-Maxwell diffusion equation describes how multiple chemical species diffuse through each other in a mixture, accounting for interactions between all species pairs. Unlike Fick's law, which assumes species diffuse independently, Stefan-Maxwell theory captures the coupling that occurs when species with different diffusivities move at different rates. This is essential for analyzing gas separation, combustion, catalytic processes, and reactive distillation.