Existence of capacity drop phenomenon, as the difference between pre-queue and queue discharge flow rates, has been one of the controversial concepts of traffic engineering. Several researches have focused on capacity drop existence and also its estimation issues. This paper aims to estimate capacity drop based not only on a comparison between breakdown and queue discharge flow rates, but also ...

abstract weirs are the most common structures for discharge measurement in engineering research. streamline curvature, non hydrostatic pressure distribution on weir and nappe adherence to the weir lead to differences between calculated and measured discharges. thus discharge coefficient, which is the ratio of real and theoretic discharges, is usually less than unity. in circular weirs the press...

Weirs, as overflow structures, are extensively used for the measurement of flow, its diversion and control in the open canals. Labyrinth weir due to more effective length than conventional weirs, allows passing more discharge in narrow canals. Determination the design criteria for the practical application of these weirs need more investigation. Weir angle and its position relative to the flow ...

Diffusion-shaped film holes with compound angles are currently being investigated for high temperature gas turbine airfoil film cooling. An accurate prediction of the coolant blowing rate through these film holes is essential in determining the film effectiveness. Therefore, the discharge coefficients associated with these film holes for a range of hole pressure ratios is essential in designing...

Soil detachment is known as an important process in soil erosion and its quantification is necessary to establish a basic understanding of erosion. This study was carried out to find the best flow erosivity indicator(s) for predicting detachment rate at low slopes. For this purpose, 12 experiments including 6 flow discharges (75, 100, 125, 150, 175 and 200 ml/s) and 2 slope gradients (1.5 and 2...

In this paper, two fluid–structure interaction (FSI) models of the discharge valve are presented to study the effect of partly covering the discharge port by the cylinder and the roller on the effective flow and force areas. One is the full FSI model and another is the simplified FSI model in which the discharge port is not covered and the cylinder shape is simplified to be cylindrical. The pre...

this study proposed a new discharge estimation method using a mean velocity formula derived from chiu’s 2d velocity formula of probabilistic entropy concept and the river bed shear stress of channel. in particular, we could calculate the mean velocity, which is hardly measurable in flooding natural rivers, in consideration of several factors reflecting basic hydraulic characteristics such as ri...

Rating curves relating stream discharge to water-surface stage are traditionally established empirically through many measurements of discharge and concurrent stage. However, discharge measurements typically scatter and do not show a unique relation to the stage because the underlying physics are usually not reflected in the rating. Examining the relationship of stage versus discharge in open c...