fluid flow

…mechanics, science concerned with the response of fluids to forces exerted upon them. It is a branch of classical physics with applications of great importance in hydraulic and aeronautical engineering, chemical engineering, meteorology, and zoology.

) Evolution in a different direction began when the French mathematicians Alexis Clairaut in 1740 and d’Alembert in 1752 discovered equations for fluid flow. Their equations govern the velocity components u and v at a point (x, y) in a steady two-dimensional flow. Like…

Fluid flow, in addition, is classified as compressible or incompressible on the basis of the Mach number. For example, gas flowing with a Mach number of less than three-tenths may be considered incompressible, or of constant density, an approximation that greatly simplifies the analysis of…

flow direction differs from that of the general flow; the motion of the whole fluid is the net result of the movements of the eddies that compose it. Eddies can transfer much more energy and dissolved matter within the fluid than can molecular diffusion in…

…when under shear stress constitutes flow, a characteristic property of fluids. In contrast, the shearing forces within an elastic solid, held in a twisted or flexed position, are maintained; the solid undergoes no flow and can spring back to its original shape. (See deformation and flow.) Compressed fluids can spring…

Oxygen is usually administered in controlled amounts per minute, a measure known as the flow rate. Flow rate is determined based on measurements of a patient’s blood oxygen levels. Two tests that are commonly used to assess the concentration of oxygen in the…

…the differential equations that describe fluid motion (see fluid mechanics).

…in the mathematical description of fluid motion, in which the local velocity v(r) of fluid particles constitutes a field to which the notions of divergence and curl are naturally applicable.

The flow rate or discharge of a river varies with time. Higher flow rates typically occur in the spring, and lower flow rates occur in the winter, though this is often not the case in areas with monsoon systems. When the average discharge of a river…

The Congo has a regular flow, which is fed by rains throughout the year. At Kinshasa the flow has for many years remained between the high level of 2,310,000 cubic feet (65,000 cubic metres) per second, recorded during the flood of 1908, and the low level of 756,000 cubic feet…

Flow rates in the interior of an ice sheet are very low, being measured in centimetres or metres per year, because the surface slope is minuscule and the ice is very cold. As the ice moves outward, the rate of flow increases to a few…

These glaciers generally flow at rates of 0.1 to 2 metres per day, faster at the surface than at depth, faster in midchannel than along the margins, and usually fastest at or just below the equilibrium line. Cold, polar glaciers flow relatively slowly, because the constitutive law of…