| 释义 |
Darcy|ˈdɑːsɪ|
[The name of H. P. G. Darcy (1803–58), inspector of the Paris waterworks.]
1. Used attrib. and in the possessive to designate concepts arising out of Darcy's work on fluid flow, esp. in Darcy's law, a law governing the flow of fluid through a porous medium, according to which the volume flow per unit cross-sectional area is proportional to the pressure gradient divided by the viscosity of the fluid.
1881Encycl. Brit. XII. 493/2 (heading) Ganguillet & Kutter's modified Darcy formula. 1931Physics I. 35 In the case of the flow of liquids through porous media..the empirically established law (D'Arcy law [sic]) that the velocity is proportional to the pressure gradient has been taken as the basis of the hydrodynamics. 1957Nature 23 Feb. 407/2 The section concerned with underground water devoted most of the sessions to an appreciation of the so-called Darcy's Law and its application and validity over a wide range of ground-water problems. 1972R. G. Kazmann Mod. Hydrol. (ed. 2) v. 184 It is only in connection with water flow in the vicinity of discharging wells that..the flow is often turbulent, and Darcy's law does not apply.
2. Written darcy (pl. darcys, darcies). A c.g.s. unit of permeability to fluid flow, being the permeability of a medium that allows a flow of 1 cubic centimetre per second of a liquid of 1 centipoise viscosity under a pressure gradient of 1 atmosphere/centimetre.
1933R. D. Wyckoff et al. in Rev. Sci. Instruments IV. 395/2 In view of Darcy's fundamental work in establishing the laws of flow for porous media it has seemed appropriate to name the unit of permeability the darcy. 1971Bull. Amer. Assoc. Petroleum Geologists LV. 1694/2 Average porosity is about 34%, and average permeability is in excess of 3 darcys. 1975G. Anderson Coring i. 15 The American Petroleum Institute has modified the darcy to standardize its use for the petroleum industry. |