fluid pressure
Quick Summary
In physics, pressure is defined as the perpendicular force acting on a unit area of a surface. It is the stress at a point within a confined fluid. This pressure can be exerted by solids, liquids, or gases.12
Pascal's principle states that in a fluid at rest within a closed container, any change in pressure applied to one part of the fluid is transmitted undiminished to every portion of the fluid and to the walls of the container. This principle is fundamental to understanding how hydraulic systems work, such as hydraulic brakes and presses, where a small force applied to a small area can generate a much larger force on a larger area.3
Pressure increases with depth in a fluid due to the weight of the fluid above. For example, atmospheric pressure is the weight of the air pressing down on Earth's surface, and it decreases with altitude.41
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fluid mechanicsBasic properties of fluids…arises when adjacent layers of fluid slip over one another. It follows that the shear stresses are everywhere zero in a fluid at rest and in equilibrium, and from this it follows that the pressure (that is, force per unit area) acting perpendicular to all planes in the fluid is…
Read More…arises when adjacent layers of fluid slip over one another. It follows that the shear stresses are everywhere zero in a fluid at rest and in equilibrium, and from this it follows that the pressure (that is, force per unit area) acting perpendicular to all planes in the fluid is…
Read More- fluid mechanicsConvection
Consequently, the vertical pressure gradient which satisfies equation (123) in the rest of the air is too large to keep the layer adjacent to the radiator in equilibrium; that layer rises and, similarly, the cold layer adjacent to the wall falls. A circulating pattern of thermal convection is…
Read MoreConsequently, the vertical pressure gradient which satisfies equation (123) in the rest of the air is too large to keep the layer adjacent to the radiator in equilibrium; that layer rises and, similarly, the cold layer adjacent to the wall falls. A circulating pattern of thermal convection is…
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pressureHydrostatic pressure is the stress, or pressure, exerted equally in all directions at points within a confined fluid (liquid or gas). It is the only stress possible in a fluid at rest. See Pascal’s principle.
Read MoreHydrostatic pressure is the stress, or pressure, exerted equally in all directions at points within a confined fluid (liquid or gas). It is the only stress possible in a fluid at rest. See Pascal’s principle.
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biosphereHydrostatic pressureBecause air and water have vastly different densities, the pressures experienced in terrestrial and aquatic habitats differ markedly. A column of water, so much denser than air, exerts a greater amount of pressure than a column of air. With each 10-metre (32.8-foot) increase…
Read MoreBecause air and water have vastly different densities, the pressures experienced in terrestrial and aquatic habitats differ markedly. A column of water, so much denser than air, exerts a greater amount of pressure than a column of air. With each 10-metre (32.8-foot) increase…
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phaseApplications to petrology…thus favoured (enlarged) with increasing pressure.
Read More…thus favoured (enlarged) with increasing pressure.
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rockRock mechanics…of pressure may be simulated: confining (hydrostatic), due to burial under rock overburden, and internal (pore), due to pressure exerted by pore fluids contained in void space in the rock. Directed applied stress, such as compression, tension, and shear, is studied, as are the effects of increased temperature introduced with…
Read More…of pressure may be simulated: confining (hydrostatic), due to burial under rock overburden, and internal (pore), due to pressure exerted by pore fluids contained in void space in the rock. Directed applied stress, such as compression, tension, and shear, is studied, as are the effects of increased temperature introduced with…
Read More- rockEffect of environmental conditions
(1) Confining pressure increases the elasticity, strength (e.g., yield point and ultimate fracture stress), and ductility. (2) Internal pore-fluid pressure reduces the effective stress acting on the sample, thus reducing the strength and ductility. The effective, or net, confining pressure is the external hydrostatic pressure minus…
Read More(1) Confining pressure increases the elasticity, strength (e.g., yield point and ultimate fracture stress), and ductility. (2) Internal pore-fluid pressure reduces the effective stress acting on the sample, thus reducing the strength and ductility. The effective, or net, confining pressure is the external hydrostatic pressure minus…
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