Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1916 edition. Excerpt: ...discharge have been obtained ranging from 0.90 to 0.975 in those of perfect form; but 0.94 is usually named as a suitable mean for general use. Discharge Through Expanding Tubes Of Moderate Length The mean velocity through an orifice may be increased considerably beyond the theoretical velocity due to the head, by attaching to the outer end of the opening a divergent or expanding discharge. For a discussion of the principles involved, see the later editions of Trautwine's handbook; but a brief dynamic outline of the theory is as follows: As the particles issue from the orifice, a, b, Fig. 10, and plunge into others that are moving more quietly, their velocity is arrested by, and their momentum imparted to the liquid which occupies the expanding ajutage X, with a resulting tendency to drive this conical section from the tube. When the exit is immersed as in the figure, this cannot occur; and the action, or tendency to act, results in a partial vacuum in the region a, b, which reinforces the atmospheric pressure upon the surface of the liquid above the natural head to the measure of the vacuum formed, and accelerates the velocity through the orifice beyond that naturally due to the fall. Coefficients of discharge ranging from about 0.90 to nearly 1.50 have been obtained through tubes similar to the one illustrated; but the many ratios of diameter to length, and the great variety of divergent angles, make it impracticable to name a single coefficient that would be generally applicable. That the class of orifice and the coefficients appropriate for each may be readily found, I recapitulate as follows: Coeff. First. Through thin plates, or partitions two diameters or less in thickness, with full contraction, use 0.61 When thin tubes project...
