| Fig. 100. |
Variation of Velocity in the Pipe.—Let p0, u0 be the pressure and velocity at a given section of the pipe; p, u, the pressure and velocity at any other section. From equation (3a)
up = cτW / Ω = constant;
so that, for any given uniform pipe,
| up = u0p0, u = u0p0 / p; |
(12)
which gives the velocity at any section in terms of the pressure, which has already been determined. Fig. 101 gives the velocity curves for the two experiments of Culley and Sabine, for which the pressure curves have already been drawn. It will be seen that the velocity increases considerably towards that end of the pipe where the pressure is least.
| Fig. 101. |
§ 93. Weight of Air Flowing per Second.—The weight of air discharged per second is (equation 3a)—
W = Ωu0p0 / cτ.