Application of Boundary Layer Theory to Explain Some Nozzle and Venturi Flow Peculiarities

Abstract

The basis of a simple rational method for the analytical determination of discharge coefficients for the rounded-entrance nozzle and Venturi, covering the entire Reynolds number range, is presented. Certain experimental results, when compared with the theoretically derived curves, support the method. Tentative explanations are given, with the aid of the theory, for a number of puzzling and disturbing features arising from the results of some recent flowmeter calibrations. The analysis includes a new method of plotting the discharge coefficient against Reynolds number, which greatly facilitates the interpretation of experimental data.