Online Encyclopedia

chambers, &c., where the flow is dependent on a head which increases or diminishes during the operation. The simplest of these problems is the See also:

case of filling or emptying a vessel of See also:

CONSTANT, BENJAMIN (1845-1902)

constant See also:

HORIZONTAL

horizontal See also:

section. Time of Emptying or Filling a See also:

VERTICAL (from Lat. vertex, highest point)

Vertical-sided Lock Chamber.—Suppose the lock chamber, which has a See also:

WATER

water See also:

SURFACE

surface of ti square ft., is emptied through a sluice in the tail See also:

GATES, HORATIO (1728-1806)

gates, of See also:

AREA

area w, placed below the tail-water level. Then the effective head producing flow through the sluice is the difference of level in the chamber and tail See also:

bay. Let H (fig. 64) be the initial difference of level, h the difference Head water level of level after t seconds. Let —dh be the fall of level in the chamber during an See also:

INTERVAL

interval dt. Then in the time dt the See also:

VOLUME

volume in the chamber is altered by the amount —tdh, and the outflow from the sluice in the same time is cwJ (2gh)dt. Hence the See also:

DIFFERENTIAL

differential See also:

EQUATION (from Lat. aequatio, aequare, to equalize)

equation connecting h and t is cal (2gh)dt-i-ih =o. B 1==~I B is the See also:

RESERVOIR

reservoir of water to be pumped ; C is the reservoir into which the water is pumped. ~1K N\ FIG.

59. 4r. E For the time t, during which the initial head H diminishes to any other value h, {S2/(cw',/2g)} f hdh/,lh= ftdt. H 0 .'.t =2t2(V H —^( h)/{cwy' (2g) } =(S2/cw){J (2H/g) —I (2h/g)1. For the whole time of emptying, during which h diminishes from H to o, T=(S2/cw) (2H/g). Comparing this with the equation for flow under a constant head, it will be seen that the time is See also:

double that required for the discharge of an equal volume under a constant head. The time of filling the lock through a sluice in the head gates is exactly the same, if the sluice is below the tail-water level. But if the sluice is above the tail-water level, then the head is constant till the level of the sluice is reached, and afterwards it diminishes with the time.

End of Article: DISCHARGE WITH VARYING

Additional information and Comments

There are no comments yet for this article.

» Add information or comments to this article.

Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML.

Site content, images, and layout Copyright © 2006 - Net Industries, worldwide.
Do not copy, download, transfer, or otherwise replicate the site content in whole or in part.

Links to articles and home page are always encouraged.

[back]
DISCHARGE OF

[next]
DISCHARGING ARCH