. Appleton's dictionary of machines, mechanics, engine-work, and engineering. be taken of this circumstance to apply an ajutage to the orifice of the form assumed by the jet, thedischarge will be found to approximate very closely to that assigned by the theoretical formula. rhis difference of discharge in the two kinds of aperture is usually ascribed to the inclined directionswinch the molecules of the fluid assume previous to their exit, and which they tend to retain after pass-ing the thin panctes of the simple orifice. For greater clearness, let us assume that the aperture is WATER-WHEELS.
. Appleton's dictionary of machines, mechanics, engine-work, and engineering. be taken of this circumstance to apply an ajutage to the orifice of the form assumed by the jet, thedischarge will be found to approximate very closely to that assigned by the theoretical formula. rhis difference of discharge in the two kinds of aperture is usually ascribed to the inclined directionswinch the molecules of the fluid assume previous to their exit, and which they tend to retain after pass-ing the thin panctes of the simple orifice. For greater clearness, let us assume that the aperture is WATER-WHEELS. 889 Sec&7ion the 7fae 890 WATER-WHEELS. horizontal, circular, and of small area in comparison with the area of the containing vessel; under theseconditions a large portion of the fluid will be put in motion, and will slowly approach the orifice duringthe efflux, in the form of an inverted cone, of which the orifice is the apex. The particles, as they comeopposite to the orifice, are therefore impressed with motions converging to an axis ; but these motions,in consequence of the mutual cohesion of the particles, must tend to a common velocity in that axis;and the length of the external conoid will express the time in which the oblique motions are convertedinto motions parallel to the axis of the jet. It is therefore only at the point of least section that themolecules of fluid have attained the effective velocity due to the head under which they issue ; and it istherefore only in reference to that point that the hydraulic pressure of the jet is equal to a column ofthe fluid of double the actual head. By ado
Size: 1221px × 2046px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectmechanicalengineering, bookyear1861
