This paper studies the phenomenon of hydraulic jump in compound channels using a numerical model and provides remarkable results. Several values of the opening parameter, h1, are utilized to generate the hydraulic jumps. A recirculation zone is detected by studying the RNG-K-Ɛ turbulent Volume Of Fluid (VOF) model, which is distinguished by the modified directions of the velocity vectors. When comparedwith the experimental values, the numerical simulation demonstrated very good accuracy, with an error of no more than 9.4%. The results underline the reliability and usefulness of the VOF turbulence model for understanding and simulating the hydraulic processes in compound channels.

Sedimentation of dam reservoirs is a complex problem with several dimensions, including filling rates and characteristics of accumulated sediments. Sediment supply from river basins is particularly high in this region because of its semi-arid climate and especially because of poor vegetation protection. The amount of silt accumulated annually since the construction of this dam is estimated at 330000 m3. This silt accumulation strongly limits its storage capacity and consequently its operating duration. The consequences of this serious problem have been catastrophic, including a considerable reduction of 43–84% of the storage capacity of the dams and a clear degradation of water quality that can cause the degradation of the ecosystem functioning and can lead to irreversible changes. The silt present in abundance in the Algerian dams can, thus, constitute a potential resource to be judiciously exploited towards the increase of the performances of the construction materials. The extraction of sediments accumulated in the dam reservoir is, therefore, imperative. These sediments have a great geotechnical value. The objective of this study is to assess the feasibility of the recovery of mud by studying the knowledge of the sediments of the dam of Koudiat Medouar. The results of the tests carried out in laboratory allowed us to identify the various sediments from a physical and geotechnical point of view. These materials must of course meet certain rigorous criteria in terms of mechanical strength and durability and environmental impact. The experimental approach that we adopted allowed us to determine the characteristics of the materials necessary for the realization of compressed earth bricks (BTC) in conformity with the recommendations of the technical guides of construction.

Turbulent flows are characterized by the presence of "scales of fluctuations", or "structures" of varying magnitudes, the effects in which the mixing, transfer and dissipation of energy are preponderant. Most importantly, dissipation determines the depth profile of the flow. This contribution aims to implement a model able to predict unsteady turbulent flows generated by the presence of obstacles in a channel with complex geometry and to report, where the complexity of the phenomena are observed, such as: the separation of the boundary layer, the succession of vortices, local heat transfers, and the recirculation zones in the wake of obstacles and the oscillatory regime of the hydraulic jump for which this research is of exclusive interest. The current work therefore, presents the numerical simulation in unsteady turbulent regime based on the resolution of balance equations, using the RANS (Reynolds-Averaged Navier–Stokes) approach with an RNG k−ε closure model. To solve the incompressible Navier–Stokes equations governing these flows, we appealed to the motivated finite volume method, and its ability to process complex geometries. The simulation software FLUENT we used is based on the finite volume method. It allows to explore, the velocity and pressure fields in the digital channel of the studied flows.

Sedimentation of dam reservoirs is a complex problem with several dimensions, including filling rates and characteristics of accumulated sediments. Sediment supply from river basins is particularly high in this region because of its semi-arid climate and especially because of poor vegetation protection. The amount of silt accumulated annually since the construction of this dam is estimated at 330000 m³. This silt accumulation strongly limits its storage capacity and consequently its operating duration. The consequences of this serious problem have been catastrophic, including a considerable reduction of 43–84% of the storage capacity of the dams and a clear degradation of water quality that can cause the degradation of the ecosystem functioning and can lead to irreversible changes. The silt present in abundance in the Algerian dams can, thus, constitute a potential resource to be judiciously exploited towards the increase of the performances of the construction materials. The extraction of sediments accumulated in the dam reservoir is, therefore, imperative. These sediments have a great geotechnical value. The objective of this study is to assess the feasibility of the recovery of mud by studying the knowledge of the sediments of the dam of Koudiat Medouar. The results of the tests carried out in laboratory allowed us to identify the various sediments from a physical and geotechnical point of view. These materials must of course meet certain rigorous criteria in terms of mechanical strength and durability and environmental impact. The experimental approach that we adopted allowed us to determine the characteristics of the materials necessary for the realization of compressed earth bricks (BTC) in conformity with the recommendations of the technical guides of construction.

The aim of this work is to study the mechanical behavior of the sediments extracted from the Koudiet Meddaouar, Timgad dam (Algeria), for a possible valorization in the field for building works in order to minimize this phenomenon which is currently a concern for the operators and the persons in charge of the mobilization of the water resources. This siltation therefore severely limits its storage capacity and consequently it’s operating life. The extraction of the sediments accumulated in the dam’s reservoir is therefore imperative, on the pain of seeing it perish in the medium term. These sediments are, however, of great geotechnical and mechanical value. The results of the tests conducted in the laboratory have enabled us to identify the different sediments from a physical and geotechnical point of view In front of the difficulties noted in the control of the silting up of the dams in Algeria, a very important quantity of silt being deposited annually in the dams. In order to achieve our objective, different mixtures of silt with or without lime treatment, cement glass fibers and powdered fibers were studied for the possible manufacture of Compressed Earth Bricks (CEB). The results obtained show that some of the mixtures present very interesting results in the different tests (compression and bending), verifying the conditions of the standards in force and thus allowing their use in the field of the manufacture of building materials.

The Reynolds–averaged Navier–Stokes (RANS) equations were solved along with Reynolds stress model (RSM), to study the fully-developed unsteady and anisotropic single-phase turbulent flow in 90° bend pipe with circular cross-section. Two flow configurations are considered the first is without ribs and the second is with ribs attached to solid walls. The number of ribs is 14 ribs regularly placed along the straight pipe. The pitch ratios is 40 and the rib height e (mm) is 10% of the pipe diameter. Both bends have a curvature radius ratio, of 2.0. The solutions of these flows were obtained using the commercial CFD software Fluent at a Dean number range from 5000 to 40000. In order to validate the turbulence model, numerical simulations were compared with the existing experimental data. The results are found in good agreement with the literature data. After validation of the numerical strategy, the axial velocity distribution and the anisotropy of the Reynolds stresses at several downstream longitudinal locations were obtained in order to investigate the hydrodynamic developments of the analyzed flow. The results show that in the ribbed bend pipe, the maximum velocity value is approximately 47% higher than the corresponding upstream value but it is 9% higher in the case of the bend pipe without ribs. It was also found for both cases that the distribution of the mean axial velocity depends faintly on the Dean number. Finally, it can be seen that the analyzed flow in the bend pipe without ribs appears more anisotropic than in bend pipe with ribs.

In the present study, both experimental and numerical were conducted on a free surface flow over an obstacle. Numerical simulations were performed using the Renormalization Group (RNG-k-ɛ) based Reynolds-Averaged Navier–Stokes (RANS) turbulence model coupled with the Volume OF Fluid (VOF) method in FLUENT Software to investigate the effect of the channel slope on the flow pattern upstream, above and downstream the obstacle. Respectively, 5%, 7%, 8%, 10%, 20% and 50% channel slopes were considered. Numerical simulation has showed a good agreement compared against experimental results. Effect of the slope on the flow is observed particularly upstream of the obstacle where the flow takes the vertical direction after hitting the upstream wall. The more the slope becomes steeper, the higher the level of the water is. Recirculation zones in the case of a horizontal channel are elongated downstream the weir, whereas in the case of a sloped channel, they are localized just at the foot of the downstream wall.

This article is particularly interested in the numerical modeling of water hammer in a hydraulic circuit, taking into account the prevailing water temperature. The study concerns the propagation velocity of the wave and the amplitude of unsteady phenomena encountered in the circuit, as well as the severity and collapse of cavitations that are also considered as major risks. To conjecture the consequences of these phenomena, we were led to simulate a single-phase and two-phase transient flows in a hydraulic copper pipe system in a temperature range of 4–95 °C. To do this, we have developed a solver for the dynamic and continuity equations’ resolution. The method of characteristics is chosen for its capacities to solve these equations. Its application shows that it is robust and adapted to the problem studied. Two cavitations’ models and column separation have been incorporated; in this case, the Discrete Vapor Cavity Model (DVCM) and the Discrete Gas Cavity Model (DGCM). Moreover, in addition to the classic models of quasi-stable friction, of which the models of unsteady friction have been included, like the one based on the instantaneous acceleration proposed by Brunone and the one proposed by Vardy & Brown based on the convolution integral. Although single-phase and two-phase water hammers do not behave in the same way, the results obtained with these models show that the temperature produces a great effect on the hammer.

The aim of this work is to study the mechanical behavior of the sediments extracted from the Koudiet Meddaouar, Timgad dam (Algeria), for a possible valorization in the field for building works in order to minimize this phenomenon which is currently a concern for the operators and the persons in charge of the mobilization of the water resources. This siltation therefore severely limits its storage capacity and consequently it’s operating life. The extraction of the sediments accumulated in the dam's reservoir is therefore imperative, on the pain of seeing it perish in the medium term. These sediments are, however, of great geotechnical and mechanical value. The results of the tests conducted in the laboratory have enabled us to identify the different sediments from a physical and geotechnical point of view In front of the difficulties noted in the control of the silting up of the dams in Algeria, a very important quantity of silt being deposited annually in the dams. In order to achieve our objective, different mixtures of silt with or without lime treatment, cement glass fibers and powdered fibers were studied for the possible manufacture of Compressed Earth Bricks (CEB). The results obtained show that some of the mixtures present very interesting results in the different tests (compression and bending), verifying the conditions of the standards in force and thus allowing their use in the field of the manufacture of building materials.

Seismic deformation assessments are an ongoing issue in the design, monitoring and construction of earth dams. The need for new advanced methods to model their seismic behavior and to evaluate the resulting deformations is justified by the uncertainties surrounding conventional methods, mainly, with liquefaction phenomena. In this respect, the present study focuses on the prediction of relative crest settlement of embankment dams under variant earthquake loading (Δh_EQ/H). For this purpose, Back-Propagation Neural Network (BPNN) and Multivariate Adaptive Regression Splines (MARS) models were developed to predict (Δh_EQ/H). Two different databases of historically documented earthquake cases are collected for model development and comparative performance between model predictions. The first contains 151 observations of liquefied and non-liquefied cases, while the second contains only 109 non-liquefied cases. The obtained results indicated that both technics could be used as reliable tools to predict the earthquake-related crest settlement in embankment dams. Also, MARS was selected as the most successful prediction tool.