Elements of Hydraulics: A Text-book for Secondary Technical SchoolsWiley, 1912 - 156 σελίδες |
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Elements of Hydraulics: A Text-Book for Secondary Technical Schools Mansfield Merriman Δεν υπάρχει διαθέσιμη προεπισκόπηση - 2018 |
Συχνά εμφανιζόμενοι όροι και φράσεις
a₁ actual discharge approximate c₁ center of pressure channel circular orifice coefficient of contraction coefficient of discharge coefficient of velocity Compute the discharge contracted section crest cross-section cubic feet cubic foot curve D₁ depth discharge per second efficiency equal equation Fahrenheit feet long feet per second formula friction factor frustrum gravity greater h₁ h₂ head h head in friction hence horizontal horse-power hydraulic gradient inches in diameter kinetic energy length loss of head lost head MANSFIELD MERRIMAN mean value mean velocity measured meter miner's inch normal pressure nozzle P₁ percent piezometer piston Pitot tube plane pounds per square pressure-head Prob quantity of water reaction wheel rectangle rectangular reservoir rise side slope square inch standard orifice stream theoretic discharge theoretic velocity tion turbine unit-pressure valve vanes velocity of flow velocity-head vertical orifice vessel water flows water level water surface weir wetted perimeter wheel
Δημοφιλή αποσπάσματα
Σελίδα 31 - This impulse will be exerted as a pressure upon any surface placed in the path of the jet. The reaction of a jet upon a vessel occurs when water flows from an orifice. This reaction must be equal in value and opposite in direction to the impulse, as in all cases of stress action and reaction are equal. In the direction of the jet the impulse produces motion, in the opposite direction it produces a pressure which tends to move the vessel.
Σελίδα 125 - A hydraulic motor is an apparatus for utilizing the energy of a waterfall. It generally consists of a wheel which is caused to revolve, either by the weight of water falling from a higher to a lower level, or by the dynamic pressure due to the change in direction and velocity of a moving stream.
Σελίδα 23 - Fig. 22, so that a jet of water from an orifice is directed vertically upward, it is known that it never attains to the height of the level of the water in the vessel, although under favorable conditions it nearly reaches that level. It may hence be inferred that the jet would actually rise to that height were it not for the resistance of the air and the friction of the edges of the orifice. Now, since the velocity...
Σελίδα 109 - A weir is a notch in the top of the vertical side of a vessel or reservoir through which water flows. The notch is generally rectangular, and the word "weir" will be used to designate a rectangular notch unless otherwise specified, the lower edge of the rectangle being truly horizontal, and its sides vertical. The lower edge of the rectangle is called the "crest
Σελίδα 63 - ... deflected sidewise in all directions. When the nozzle is in operation, the ball is held close to the tip of the nozzle by atmospheric pressure, the negative pressure head being caused by the high velocity of the sheet of water around the ball.
Σελίδα 66 - When the flow becomes steady, the pipe is entirely filled throughout its length, and hence the mean velocity at any section is the same as that at the end, when the size is uniform. This velocity is found to decrease as the length of the pipe increases, other things being equal, and becomes very small for great lengths, which shows that nearly all the head has been lost in overcoming the resistances.
Σελίδα 42 - The Coefficient of Velocity.— The coefficient of velocity is the number by which the theoretical velocity of flow from the orifice is to be multiplied in order to find the actual velocity at the least cross-section of the jet. This may be taken for practical work as .98; or, in other words, the actual flow at the contracted section is 98$ of the theoretical velocity.
Σελίδα 137 - ... is tightened it is prevented from revolving by the tension caused by the weights. The direction of the cord in the horizontal plane must be such that the perpendicular let fall upon it from the center of the...
Σελίδα 108 - The miner's inch may be roughly defined to be the quantity of water which will flow from a vertical standard orifice one inch square, when the head on the center of the orifice is 6'/2 inches.
Σελίδα 9 - ... surface of water at rest is perpendicular to. the direction of the force of gravity, and for bodies of water of small extent this surface may be regarded as a plane. Any depth below this plane is called a "head," or the head upon any point is its vertical depth below the level surface.