Lowell Hydraulic Experiments: Being a Selection from Experiements on Hydraulic Motors, on the Flow of Water Over Weirs, in Open Canals of Uniform Rectangular Section and Through Submerged Orifices and Diverging TubesD. Van Nostrand, 1868 - 251 páginas |
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Términos y frases comunes
apertures apparatus arithmetical mean bell crank Boileau bottom brake cent chamber coefficient of effect computed consequently correction corresponding crest cubic feet cubic foot curve deduced depth of water determined diameter distance diverging tube downstream end contraction entering the wheelpit fall acting February 22 feet per second figure floating FLOW OF WATER foot forebay given in column head hook gauge boxes horizontal inches irregularities leakage length Lesbros Lowell marine chronometer Mean depth Mean height Mean shortest distance mean velocity measuring flume ment Merrimack Merrimack Canal Merrimack River mouth-piece nearly north hook gauge Number of buckets obtained orifice passing the weir pipe opening plank plate pounds avoirdupois proposed formula purpose quantity of water regulating gate represented scale of velocities stream taken tions transit station TREMONT TURBINE upstream side variations velocity due vertical water discharged water flowing WATER OVER WEIRS water passing wheel width
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Página 211 - We know now that the underlying principle is the same as in a mercurial barometer : it is the pressure of the atmosphere on the surface of the water in the well that pushes the water up into the pump.
Página 2 - House of the Appleton Company's cotton-mills, at Lowell, in Massachusetts, in which wheel, Mr. Boyden introduced several improvements, of great value. The performance of the Appleton Company's turbine, was carefully ascertained by Mr. Boyden, and its effective power, exclusive of that required to carry the wheel itself, a pair of bevel gears, and the horizontal shaft carrying the friction pulley of a Prony dynamometer, was found to be seventy-eight per cent.
Página 133 - S.S3(I,~ in which Q =: the discharge, in cubic feet per second ; L = the length of the weir ; n = the number of end contractions ; H= the depth on the weir ; the English foot being the unit of measure. When the contraction is complete at each end of the weir, n = 2 ; when the weir is of the same width as the canal conducting water to it, the end contraction is suppressed, and n — 0. This formula is only applicable to rectangular...
Página ii - FRANCIS, in the Clerk's Office of the District Court of the District of Massachusetts. PREFACE TO THE SECOND EDITION. SINCE the first edition of this work appeared, in 1855, the manufacturing corporations at Lowell, lessees of the water-power furnished by the...
Página 45 - P=the horse-power of the turbine; a horse-power being 550 pounds avoir. raised one foot per second. h = the fall acting upon the wheel. Q = the quantity of water expended by the turbine, in cubic feet per second. V= the velocity due the fall acting upon the wheel. V = the velocity of the water passing the narrowest sections of the wheel. v = the velocity of the interior circumference of the wheel : all the velocities being in feet per second.
Página 16 - The quantity of water discharged by the four jets was, by a mean of two trials, 0-0288 cubic feet per second. " In many of the experiments with heavy weights, and consequently slow velocities, oil was used to lubricate the brake, the water, during the experiment, being shut off. It is found, that, with a small quantity of oil, the friction between the brake and the pulley is much greater than when the usual quantity of water is applied ; consequently, the requisite tension of the brake screws is...
Página 28 - Magistrate having jurisdiction in such place, to ascertain the content of such measure of capacity by direct reference to the weight of pure or rain water which such measure is capable of containing. Ten pounds avoirdupois weight of such water, at the temperature of...
Página 18 - ... the weir. The depth of water flowing over the weir is the distance between the point of the hook in the position named and the exact surface of the water. To ascertain this, the hook is raised by turning the milled -head nut until the point of the hook, appearing a little above the surface, causes a distortion in the reflection of the light from- the surface of the water. A slight movement of the hook in the opposite direction will cause the distortion to disappear, and will indicate the surface...
Página 17 - ... and, consequently, when the vane was in the direction of the radius of the wheel, the hand pointed at 90°. To prevent sudden vibrations of the vane, a modification of the hydraulic regulator was attached to the lower part of the vane shaft This apparatus is represented in detail by figures 6 and 8. 44. The quantity of water discharged by the wheel was gauged at a weir erected for the purpose at the mouth of the wheelpit. It is represented on plate V. Figure 1 is a plan, and figure 2 a section,...
Página 15 - ... portion of the fluid, which must evidently pass between the edge of the piston and the cylinder ; and the area of this space being very small, compared to the area of the piston, the motion of the latter must be slow, giving time to alter the tension of the brake screws before the piston has moved far. It is plain that this arrangement must arrest all violent shocks, but, however violent and irregular they may be, it is evident, that, if the mean force of them is greater in one direction than...