∴ z + p/G = constant;
(3)
| Fig. 35. |
or the pressure varies hydrostatically as in a fluid at rest. For two stream lines in a horizontal plane, z is constant, and therefore p is constant.
Radiating Current.—Suppose water flowing radially between horizontal parallel planes, at a distance apart = δ. Conceive two cylindrical sections of the current at radii r1 and r2, where the velocities are v1 and v2, and the pressures p1 and p2. Since the flow across each cylindrical section of the current is the same,
Q = 2πr1 δv1 = 2πr2 δv2
r1v1 = r2v2
r1/r2 = v2/v1.
(4)