“convection”的概念、定义、翻译、参考文献-科学参考

convection

Physics

A process by which heat is transferred from one part of a fluid to another by movement of the fluid itself. In natural convection the movement occurs as a result of gravity; the hot part of the fluid expands, becomes less dense, and is displaced by the colder denser part of the fluid as this drops below it. This is the process that occurs in most domestic hot-water systems between the boiler and the hot-water cylinder. A natural convection current is set up transferring the hot water from the boiler up to the cylinder (always placed above the boiler) so that the cold water from the cylinder can move down into the boiler to be heated. In some modern systems, where small-bore pipes are used or it is inconvenient to place the cylinder above the boiler, the circulation between boiler and hot-water cylinder relies upon a pump. This is an example of forced convection, where hot fluid is transferred from one region to another by a pump or fan.

Chemistry

A process by which heat is transferred from one part of a fluid to another by movement of the fluid itself. In natural convection the movement occurs as a result of gravity; the hot part of the fluid expands, becomes less dense, and is displaced by the colder denser part of the fluid as this drops below it. This is the process that occurs in most domestic hot-water systems between the boiler and the hot-water cylinder. A natural convection current is set up transferring the hot water from the boiler up to the cylinder (always placed above the boiler) so that the cold water from the cylinder can move down into the boiler to be heated. In some modern systems, where small-bore pipes are used or it is inconvenient to place the cylinder above the boiler, the circulation between boiler and hot-water cylinder relies upon a pump. This is an example of forced convection, where hot fluid is transferred from one region to another by a pump or fan.

Chemical Engineering

A mode of heat transfer caused by the movement of currents within a fluid as the result of different localized densities. It is a combination of conduction within the fluid and energy transport due to fluid motion, which is either by a natural flow of density currents or by a forced fluid flow, known as natural convection and forced convection, respectively. In natural convection, the movement of fluid is due to gravitational effects in which heated fluid has less density and rises, allowing cooler and denser fluid to descend. This results in a circulating flow. In forced convection, a pump or fan is used to circulate the fluid.

Geology and Earth Sciences

1. Vertical circulation within a fluid that results from density differences caused by temperature variations. Convection currents occur in the oceans when a water mass that is denser than the water below it sinks and is replaced by lighter, warmer water.
2. In meteorology, the process in which air, having been warmed close to the ground, rises. The convective uplift of air parcels is one of the main processes leading to condensation and cloud formation. See also dish-pan experiment; forced convection; hadley cell; instability; stability.
3. Within the Earth, the radiogenic heat release results in convective motions causing tectonic plate motions. The location and configuration of the convective cells is uncertain, but they appear to be mantle-wide and marked by most heat loss along the mid-ocean ridges. The difference in temperature between upgoing and downgoing convective limbs within the mantle may be only 1–2 °C. In the upper oceanic crust, heat loss is mainly by convective circulation systems combined with thermal conduction. See also creep mechanisms; geothermal gradient; heat flow; nusselt number; rayleigh number.

Geography

The process whereby heat is transferred from one part of a liquid or gas to another, by movement of the fluid itself. Convection carries excess heat from the Earth’s surface and distributes it through the troposphere (Fanaki (1971) Boundary-Layer Met. 1, 3; Takayabu et al. (2006) J. Met. Soc. Japan 84A). Convective storms include thunderstorms, hail, tornadoes, heavy rains, and high winds; Combardo and Colle (2011) Weath. Forecasting, 26, 940 document the convective storm structures over the northeastern United States
Thermal convection (free convection) is propelled by buoyancy (R. Barry and R. Chorley 2003). Mechanical convection (forced convection) is the upward movement of an air parcel over mountains, at fronts, or because of turbulence (Sorbjan (2006) Boundary-Layer Met. 119, 1). Kijazi and Reason (2005) Theoret. & Appl. Climatol. 82, 3–4 observe that wet conditions during El Niño years are associated with enhanced convection (convection with a higher Bowen ratio). See Ludlam and Scorer (2006) Qly. J. Royal Met. Soc. 79, 341.

单词	convection
释义	convection Physics A process by which heat is transferred from one part of a fluid to another by movement of the fluid itself. In natural convection the movement occurs as a result of gravity; the hot part of the fluid expands, becomes less dense, and is displaced by the colder denser part of the fluid as this drops below it. This is the process that occurs in most domestic hot-water systems between the boiler and the hot-water cylinder. A natural convection current is set up transferring the hot water from the boiler up to the cylinder (always placed above the boiler) so that the cold water from the cylinder can move down into the boiler to be heated. In some modern systems, where small-bore pipes are used or it is inconvenient to place the cylinder above the boiler, the circulation between boiler and hot-water cylinder relies upon a pump. This is an example of forced convection, where hot fluid is transferred from one region to another by a pump or fan. Chemistry A process by which heat is transferred from one part of a fluid to another by movement of the fluid itself. In natural convection the movement occurs as a result of gravity; the hot part of the fluid expands, becomes less dense, and is displaced by the colder denser part of the fluid as this drops below it. This is the process that occurs in most domestic hot-water systems between the boiler and the hot-water cylinder. A natural convection current is set up transferring the hot water from the boiler up to the cylinder (always placed above the boiler) so that the cold water from the cylinder can move down into the boiler to be heated. In some modern systems, where small-bore pipes are used or it is inconvenient to place the cylinder above the boiler, the circulation between boiler and hot-water cylinder relies upon a pump. This is an example of forced convection, where hot fluid is transferred from one region to another by a pump or fan. Chemical Engineering A mode of heat transfer caused by the movement of currents within a fluid as the result of different localized densities. It is a combination of conduction within the fluid and energy transport due to fluid motion, which is either by a natural flow of density currents or by a forced fluid flow, known as natural convection and forced convection, respectively. In natural convection, the movement of fluid is due to gravitational effects in which heated fluid has less density and rises, allowing cooler and denser fluid to descend. This results in a circulating flow. In forced convection, a pump or fan is used to circulate the fluid. Geology and Earth Sciences 1. Vertical circulation within a fluid that results from density differences caused by temperature variations. Convection currents occur in the oceans when a water mass that is denser than the water below it sinks and is replaced by lighter, warmer water. 2. In meteorology, the process in which air, having been warmed close to the ground, rises. The convective uplift of air parcels is one of the main processes leading to condensation and cloud formation. See also dish-pan experiment; forced convection; hadley cell; instability; stability. 3. Within the Earth, the radiogenic heat release results in convective motions causing tectonic plate motions. The location and configuration of the convective cells is uncertain, but they appear to be mantle-wide and marked by most heat loss along the mid-ocean ridges. The difference in temperature between upgoing and downgoing convective limbs within the mantle may be only 1–2 °C. In the upper oceanic crust, heat loss is mainly by convective circulation systems combined with thermal conduction. See also creep mechanisms; geothermal gradient; heat flow; nusselt number; rayleigh number. Geography The process whereby heat is transferred from one part of a liquid or gas to another, by movement of the fluid itself. Convection carries excess heat from the Earth’s surface and distributes it through the troposphere (Fanaki (1971) Boundary-Layer Met. 1, 3; Takayabu et al. (2006) J. Met. Soc. Japan 84A). Convective storms include thunderstorms, hail, tornadoes, heavy rains, and high winds; Combardo and Colle (2011) Weath. Forecasting, 26, 940 document the convective storm structures over the northeastern United States Thermal convection (free convection) is propelled by buoyancy (R. Barry and R. Chorley 2003). Mechanical convection (forced convection) is the upward movement of an air parcel over mountains, at fronts, or because of turbulence (Sorbjan (2006) Boundary-Layer Met. 119, 1). Kijazi and Reason (2005) Theoret. & Appl. Climatol. 82, 3–4 observe that wet conditions during El Niño years are associated with enhanced convection (convection with a higher Bowen ratio). See Ludlam and Scorer (2006) Qly. J. Royal Met. Soc. 79, 341.
随便看	g-force GFP GFR GHA Ghana Ghana, kingdom of Ghaznavid GHB Ghent, Pacification of (1576) Ghent, Treaty of (1814) ghetto GHGSat-D GHOST ghost ghost copying ghost crater ghost dance ghost imaging ghosting ghost in the machine Ghost of Jupiter ghost stratigraphy ghrelin Ghyben–Herzberg relationship GI