| 释义 |
laminar, a.|ˈlæmɪnə(r)|
[f. lamina + -ar. Cf. F. laminaire.]
1. Consisting of or arranged in laminæ, thin plates, or layers.
1811Pinkerton Petral. I. 220 Laminar pitch-stone, in thin horizontal layers. 1845Petrie Round Towers Irel. ii. iii. 210 Bracteati—by which is understood, thin laminar pieces, usually of silver. 1854Woodward Mollusca ii. 214 Discina and Lingula consist almost entirely of a horny animal substance, which is laminar. 1875Blake Zool. 202 Gills laminar, with a small proportion of the border free. 1876Harley Mat. Med. (ed. 6) 75 Soft laminar crystals.
2. a. Physics. Of the flow of a fluid: smooth and regular, the direction of motion at any point remaining constant as if the fluid were moving in a series of layers sliding over one another without mixing; occas. restricted to the case in which the layers are plane (cf. lamellar a. 2).
1895H. Lamb Hydrodynamics iii. 34 This analysis may be illustrated by the so-called ‘laminar’ motion of a liquid. 1949H. F. P. Purday Streamline Flow i. 6 In laminar flow in the strict use of the term, the fluid moves in a system of parallel planes, the velocity having everywhere the same direction, but the magnitude of the velocity is a function of the distance from some fixed plane of the system. The motion is not necessarily steady; it may, for instance, be periodic. 1965D. A. Gilbrech Fluid Mech. (1966) vi. 265 In general, laminar flow occurs at low velocities, between close boundaries, when the fluid is very viscous, and when the fluid is of low density. 1968Passmore & Robson Compan. Med. Stud. I. xxix. 8/2 Flow of gas through tubes is laminar at slow speeds, but at faster rates of flow molecular collisions set up eddies and the flow is then turbulent.
b. transf. Applied to a body whose shape is such as to produce a laminar flow of fluid in the boundary layer round it (at normal speeds).
1955J. Kestin tr. Schlichting's Boundary Layer Theory xiii. 229 The prevention of transition on laminar aerofoils. 1963Ann. Reg. 1962 390 Handley Page continued the development of their laminar wing project, in which hundreds of small slits in an aircraft wing were used to suck air away from the so-called boundary layer around the wing and thus to reduce friction and hence fuel costs. |