Principles of Construction and Efficiency of Water-wheelsE. & F. N. Spon, 1876 - 94 páginas |
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Principles of Construction and Efficiency of Water-wheels William Donaldson Visualização completa - 1876 |
Principles of Construction and Efficiency of Water-wheels William Donaldson Prévia não disponível - 1876 |
Principles of Construction and Efficiency of Water-wheels William Donaldson Prévia não disponível - 2018 |
Termos e frases comuns
absolute path angular velocity ascertain axis B₁ B₂ best velocity breast wheels centre centrifugal force chord circumference co-efficient of efficiency component corresponding cubic feet curve D₁ depth direction of motion discharging side due to friction effective power developed equal to v₁ equation experiments fall final absolute velocity flat vane greater gross power guide blades guide-blade chamber head due head lost height due impact inches increase initial radius initial velocity inward-flow turbines jet strikes leaving friction less maximum moving force exerted normal outward-flow turbines p² p² p²)² parallel-flow turbines particle periphery plane pressure quantity of water radial velocity radii radius vector ratio receiving side relative path relative velocity revolving drum right angles Ro² sluice strikes the vane tail water tangent theoretical undershot wheels v₁ sin v₁² vertical vis viva weir whole head
Passagens mais conhecidas
Página 72 - ... to which, by the balancing of the contrary fluid pressures due to half the head of water and to the centrifugal force of the water in the wheel, combined with the pressure due to the ejection of the water backwards from the inner ends of the vanes of the wheel when they are curved, only one-half of the work due to the fall is spent in communicating vis viva to the water, to be afterwards taken from it during its passage through the wheel ; the remainder of the work being communicated through...
Página 72 - ... at the circumference of the wheel, in the condition of fluid pressure. Now, with the velocity already assigned to the wheel, it is found that this fluid pressure is exactly that which is requisite to overcome the centrifugal force of the water in the wheel, and to bring the water to a state of rest at its exit ; the mechanical work due to both halves of the fall being transferred to the wheel during the combined action of the moving water and the moving wheel. In the foregoing statements, the...
Página 8 - The object of the second law of motion is to assert that the effect produced by a force is irrespective of the previous motion of the body : it is enunciated thus : — ' When a force acts on a body in motion, the velocity it would produce in the body...
Página 80 - It is somewhat remarkable, that though the velocity of the wheel in relation to the water turns out greater than 4- of the velocity of the water, yet the impulse of the water in the case of a maximum is more than double of what is assigned by theory ; that is, instead of J of the column, it is nearly equal to the whole column.
Página 72 - ... wheel ; but, on the contrary, the water enters the radiating conduits of the wheel gently, that is to say, with scarcely any motion in relation to their mouths. In order to attain the equalization of these velocities, it is necessary that the circumference of the wheel should move with the velocity which a heavy body would attain in falling through a vertical space equal to half the vertical fall of the water, or in other words, with the velocity due to half the fall ; and that the orifices through...
Página 72 - Another adaptation in the vortex is to be remarked as being highly beneficial, that, namely, according to which, by the balancing of the contrary fluid pressures due to half the head of water and to the centrifugal force of the water in the wheel, combined with the pressure due to the ejection of the water backwards from the inner ends of the vanes of the wheel when they are curved, only one-half of the work due to the fall is spent in communicating vis viva to the water, to be- afterwards taken...
Página 6 - ... into the air vessel by pumping, as there is forced out by the pressure of the air, there will be a constant jet of water. The force necessary to raise the piston in this pump, is found exactly in the same way as for the suction pump. And the force necessary to depress the piston, is found by taking the weight of a column of water, whose height is equal to the height of the spout where the water is delivered above the level of the piston, before it begins to descend. Thus, if the piston when raised...