21 Facts About Free convection

Granular Free convection is a similar phenomnon in granular material instead of fluids.

The broader sense is in fluid mechanics, where Free convection refers to the motion of fluid driven by density difference.

In broad terms, Free convection arises because of body forces acting within the fluid, such as gravity.

Natural Free convection can occur when there are hot and cold regions of either air or water, because both water and air become less dense as they are heated.

Natural Free convection has attracted a great deal of attention from researchers because of its presence both in nature and engineering applications.

In nature, Free convection cells formed from air raising above sunlight-warmed land or water are a major feature of all weather systems.

In engineering applications, Free convection is commonly visualized in the formation of microstructures during the cooling of molten metals, and fluid flows around shrouded heat-dissipation fins, and solar ponds.

Natural Free convection will be more likely and more rapid with a greater variation in density between the two fluids, a larger acceleration due to gravity that drives the Free convection or a larger distance through the convecting medium.

Natural Free convection will be less likely and less rapid with more rapid diffusion or a more viscous fluid.

However, all types of buoyant Free convection, including natural Free convection, do not occur in microgravity environments.

Gravitational Free convection is a type of natural Free convection induced by buoyancy variations resulting from material properties other than temperature.

For example, gravitational Free convection can be seen in the diffusion of a source of dry salt downward into wet soil due to the buoyancy of fresh water in saline.

Thermomagnetic Free convection can occur when an external magnetic field is imposed on a ferrofluid with varying magnetic susceptibility.

Mantle Free convection is the slow creeping motion of Earth's rocky mantle caused by Free convection currents carrying heat from the interior of the earth to the surface.

Mantle Free convection is the result of a thermal gradient: the lower mantle is hotter than the upper mantle, and is therefore less dense.

Mantle Free convection occurs at rates of centimeters per year, and it takes on the order of hundreds of millions of years to complete a cycle of Free convection.

Therefore, Grashof number can be thought of as Reynolds number with the velocity of natural Free convection replacing the velocity in Reynolds number's formula.

Grashof number can be formulated for natural Free convection occurring due to a concentration gradient, sometimes termed thermo-solutal Free convection.

Natural Free convection is highly dependent on the geometry of the hot surface, various correlations exist in order to determine the heat transfer coefficient.

One example of natural Free convection is heat transfer from an isothermal vertical plate immersed in a fluid, causing the fluid to move parallel to the plate.

Convection, especially Rayleigh–Benard Free convection, where the convecting fluid is contained by two rigid horizontal plates, is a convenient example of a pattern-forming system.