Engineering Bulletin Volume 7-24

Engineering Bulletin Volume 7-24

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 edition. Excerpt: ...the post from which the depths are to be measured. (See Fig.3). I. 1 water will enter without eddies or disturbances. The channel of the! ' ditch should have a uniform grade and cross section for 100 feet I upstream from the flume, if possible, and its axis should pass through and parallel to the middle of the structure. I I l I I. I _ ' ' i i ii The end and bottom contractions of the stream pouring over, X, . the weir must be complete. To secure this: (a) The opening in the S' weir must be in a plane surface perpendicular to the course of the water; (b) the upstream edge must be beveled to a sharp crest; (c) the distance of the crest of the weir from the bottom of the flume must be three times the maximum depth of the water intended to pass over the weir; (d) the distance from the ends of the crest of the weir to sides of the flume should be not less than twice the maximum depth of water to flow over the weir. The greatest depth of water allowable on the crest of the weir should be not more than one-third, or better, 0ne--fourth the length of the crest of the weir, and the depth should be not less than three inches. Where these conditions are not met, it would be better to use a longer weir where the depth of water fiowing over the crest is more than one third the length of the weir or a shorter one where the flow over the weir is less than three inches. The measuring post can be nailed either to the bottom or the sides of the flume and should be placed three or four feet back of the weir board. Into the top of said post drive a nail, the head of which is exactly level with the crest of the weir. In the Cippoletti weir it will be noticed that the opening or notch is of regular trapezoidal form; that is, the top and...
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Product details

  • Paperback | 44 pages
  • 189 x 246 x 2mm | 95g
  • United States
  • English
  • black & white illustrations
  • 1236945727
  • 9781236945723