Convection

Fluid flow that occurs due to heterogeneous fluid properties and body forces

Convection is the transfer of heat through the physical movement of fluids (liquids or gases), where warmer, less-dense material rises and cooler, denser material sinks. It is a single-phase or multiphase fluid flow that occurs spontaneously through the combined effects of material property heterogeneity and body forces on a fluid. When the cause of the convection is unspecified, convection due to the effects of thermal expansion (change in density) and gravity/buoyancy can be assumed (see convection in heat transfer).

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