Author(s): Oscar Castro-Orgaz
Keywords: Critical flow; discharge; flume; Khafagi flume; measurement; one-dimensional flow; open channel
Abstract: Venturi flumes are of practical significance for flow measurement structures in open channels. The curvilinear flow in these structures has not yet received a systematic attention. As a result, the current engineering practice is based on the hydrostatic pressure distribution at the flume throat. An improved critical flow theory was developed to account for curvilinear flow effects of streamlined flumes with a circular arc-shaped inlet, commonly called the Khafagi flume.A detailed study of the discharge characteristics, which is currently not available, demonstrated that the approximate potential flow equation agrees with experiments up to a flume curvature parameter of U = 4. The proposed curved streamline flow model was also corrected to account for real fluid flow effects to its direct use in engineering practice. A new design approach was proposed which is illustrated by a step-by-step procedure with a numerical example.