Page:Dictionary of aviation.djvu/265

 DICTIONARY OF AVIATION 241

vortex 'vo:z,teks n. [plural vortices, vortexes] a whirl of fluid, as the air in a smokesring; also, a whirling or gyra- tory motion; a gyre; an eddy.

vortex-core 've:z-teks,ko:z n. the core or innermost centra] nuclear part of a verteks or whirl of air.

vortex-cylinder 've:z-teks,silin-d9z n. the cylinder?shaped part of a vertex; a cylindrical vertex.

vortex-filament 've:z-teks,fil9-m3nt n. the portion of fluid included within a vertex^tube.

vortex-fringe 'veiz-teks^smds n. the upward circulatory fringe, or system of vertical currents produced at the edges of a henzental plane falling thru the air or other fluid.

vortex-knot 've:z-teks,net n. a knetelike vertex; a compli- cated gyre or eddy, as in an air^stjeam.

vortex-hoop 've:z-teks,houp n. an imaginary uncreatable and undestr.uctible vertex in an inviscid gas, shaped like a hoop or half?rmg.

vortex-motion 've:z-teks,moo-$3n n. the motion charac- teristic of a vertex; a rotational motion of a fluid in luhich there is circulation about certain vertex^filaments, and no circulation except about them.

vortex-ring 've:z-teks,zirj n. a vertical molecular filament or column returning into itself so as to form a ring com- posed of a number of small rotating circles arranged like beads on a string, as the air in a smoke^rmg.

vortex roller, a series of vertexsfilaments following each other in rapid succession and acting as rollers between the live fluid and the ded^water.

vortex-train 've:z-teks,teen n. a tgain of vertices, as the vertex^cylinders of air, collectivly, left trailing behind an aerofeil in flight.

vortex-trunk / ve:^-teks,tArjk n. a tgunk, twisted column, or heliceid cloud composed of vertex^filaments wound round each other like the strands of a rope.

vortex-tube 've:z-teks,tc,uub n. an imaginary tube, within a fluid, whose surface is the locus of vertex^lines thru a small closed curv drawn arbitrarily.

vortical 'verz-ti-kal adj. ef or like a vertex or gyre : as, a
 * vertical system of air^currents.

vortices 've:z-ti,siz n. pi. see vortex.

vulture 'vAlt$3z n. any one of various large birds of prey of the erder Raptores, having the hed and neck more or less bare of fethers, and furnisht with powerful beak and claws.

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