How Diffusion Shapes Heat in Everyday Materials
Diffusion—the net movement of thermal energy through materials driven by temperature differences—lies at the heart of heat transfer across fluids and solids. By enabling energy to flow from hotter to cooler regions, diffusion governs how buildings stay warm, roads endure thermal stress, and even materials respond to sunlight. It is a foundational principle in thermodynamics and material science, explaining how microscopic particle motion collectively creates predictable macroscopic thermal patterns.
Core Physics: From Navier-Stokes to Thermal GradientsIn fluids, heat transport arises from both conduction and convection, described mathematically by the Navier-Stokes equations—four coupled partial differential equations that capture velocity fields and pressure variations in three dimensions. These equations reveal how fluid flow velocity interacts with temperature gradients,