A treatise on physics; v.1. Dynamics and properties of matter
Andrew Gray
Paperback
(RareBooksClub.com, May 9, 2012)
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1901 Excerpt: ... side branch with the space from which the water is to be drawn. The flow of the water along the constricted neck of T gives by Bernoulli's theorem a lower pressure at the constriction than at the part beyond, and there is consequently a flow of fluid from the space surrounding and behind the nozzle. The increasing pressure from the constricted part of T forwards is employed in retarding the fluid flowing into it. The pump may be employed of course to transfer one fluid from the spice by means of a jet of another fluid applied by P. In this case a mixture of the two fluids is delivered by T to the delivery pipe. We shall suppose that the average pressure of the fluid in the nozzle is pv in the surrounding pipe pv and in the delivery pipe p, while the densities of the fluids and their velocities are p,, p,, p, vlt i, v respectively, while the areas of delivery in the three cases are av ar a. The momentum carried in by the jet in unit of time is p,»,«., and the rate at which momentum is generated by the pressure is /,«, similarly in the other cases. The rate at which momentum is delivered by the jet and the surrounding pipe is therefore (pl + plv')al + (pt + p1vf)ur The momentum delivered per second across a cross-section of the delivery tube is (p + pv)a, and we have (Pt + P.VK + (f, + P.»ii = (P + P1)"-(51) Besides this we have the equation of continuity, namely, the condition that as much matter is delivered as flows from the two jets. This condition is iPii + lWi = ar,»-52) Of course the engineering student will understand that here and elsewhere, if pressure is measured in pounds per square foot or square inch, the p in the formula as written above is g (that is 82-2) times the pressure thus reckoned, and equation (iil) will...