Failures of barrages or regulators or parts of them may be expected when excessive scour patterns are observed downstream of such structures. Severe and excessive scour may be largely due to unsymmetric operation of gates especially when a multi-vents barrages or regulator is being considered. Previous investigations proved that the scour patterns downstream hydraulic structures are functions o...

This paper considers the large-scale dynamics generated in the upper atmosphere by the destabilization of a linear internal gravity wave and its eventual restabilization through nonlinear processes into a coherent pattern. The assumption of a strongly dissipative medium is relevant to wave propagation in the thermosphere range above 100 km. A parametric instability analysis is carried out invol...

(i) For laminar flow (1) has been derived in [7] for f = −H ′′. A first analysis of that case is in [6]. Moreover this equation is also considered in the context of shock profiles in plasmas [2]. (ii) For turbulent flow in a certain distinguished limit concerning the Reynolds number and the Froude number eq. (1) has been derived in [3,4] with f = H . A multiple scales analysis of the full flow ...

The main purpose of this study is to provide a method to increase energy dissipation on an inclined drop. Therefore, three types of rough elements with cylindrical, triangular and bat-shaped geometries are used on the inclined slope in the relative critical depth range of 0.128 to 0.36 and the effect of the geometry of these elements is examined using Flow 3D software. The results showed demons...

In order to increase the efficiency of the conveyance of the granular solids, a new experimental set-up is designed. The test rig has longitudinal trapezoidal slots in its conveying pipes. Through experimentation, a correlation for friction factor in terms of solid mass flow rate, fluid flow rate and Froude number is presented. It is shown that the mixture friction factor for pipes with inn...