Publications Scientifiques
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Item Study of nanofluids cavitating flow through a venturi using computational fluid dynamics code(Publishing House of the Romanian Academy, 2025) Benghalia I.; Nehaoua N.; Zamoum M.; Ami I.In this work, we conducted a numerical study of cavitating nanofluid flow through a Venturi. The objective is to investigate the influence of nanoparticles in the base fluid on the cavitation phenomenon. The computational fluid dynamics code (CFD) was selected with a cavitation model. The mixture model for multiphase flow and the k-ω SST turbulence model were adopted. Three fluids were chosen: water, Cu/water and TiO2/water with different volume franctions of nanoparticle (0%, 10% 20%, 30%). The simulation was conducted with inlet and outlet pressures set at 700 kPa and atmosphere pressure respectively. The numerical results are compared with the previous experimental and numerical data for flow without nanoparticle. The obtained results found that, the presence of the nanoparticles in the base fluid lead to a slight increase in the static pressure, the position of pressure recovery a significant decrease in fluid velocity and an increase in the vapor fraction formation in the flow. Also, the increase of the nanoparticle volume fractions φ results a decrease in the pressure recovery position, fluid velocity and an increase in the vapor fraction formation. Therefore, the presence of nanoparticles in the base fluid promotes the phenomenon of cavitationItem Study of nanofluids cavitating flow through a venturi using computational fluid dynamics code(2025) Benghalia, Imen; Nehaoua, N.; Zamoum, M.; AMI, I.In this work, we conducted a numerical study of cavitating nanofluid flow through a Venturi. The objective is to investigate the influence of nanoparticles in the base fluid on the cavitation phenomenon. The computational fluid dynamics code (CFD) was selected with a cavitation model. The mixture model for multiphase flow and the k-ω SST turbulence model were adopted. Three fluids were chosen: water, Cu/water and TiO2/water with different volume franctions of nanoparticle (0%, 10% 20%, 30%) . The simulation was conducted with inlet and outlet pressures set at 700 kPa and atmosphere pressure respectively. The numerical results are compared with the previous experimental and numerical data for flow without nanoparticle. The obtained results found that, the presence of the nanoparticles in the base fluid lead to a slight increase in the static pressure, the position of pressure recovery a significant decrease in fluid velocity and an increase in the vapor fraction formation in the flow. Also, the increase of the nanoparticle volume fractions φ results a decrease in the pressure recovery position, fluid velocity and an increase in the vapor fraction formation. Therefore, the presence of nanoparticles in the base fluid promotes the phenomenon of cavitation.Item Split Control Wind Turbine Airfoil noise with CFD and Acoustic Analogies(Isfahan University of Technology, 2024) Khenfous, Soumia; Maizi, Mohamed; Zamoum, MohammedThis research aims to investigate the impact of a split airfoil on noise emissions from a horizontal-axis wind turbine. The objective is to comprehensively understand the airflow patterns around the airfoil to reduce noise emissions. The study rigorously examines a range of angles of attack, from 0° to 25°, for both the original airfoil and the airfoil with a split, using advanced computational aerodynamics coupled with analog acoustic analysis. The methodology involves two-dimensional flow simulations with Delayed Detached Eddy Simulation based on the Spalart-Allmaras model, enabling precise near-field flow calculations around the airfoil. Additionally, far-field noise predictions, employing the Ffowcs Williams and Hawkings analogy based on simulated sources, reveal the efficacy of the split airfoil design. Results indicate that the split airfoil design effectively reduces noise emissions across various angles of attack. These reductions translate into a significant decrease in the Overall Sound Pressure Level, ranging from 14% to 19%, and remarkable Sound Pressure Level reductions between 12% and 60% across diverse frequencies, showcasing substantial noise improvements in various frequency ranges.Item Numerical study of the performance loss of a centrifugal pump carrying emulsion(2021) Achour, Lila; Mathieu, Specklin; Belaidi, Idir; Kouidri, SmaineThe performance and hydrodynamic behavior of cen- trifugal pumps when handling two-phase liquid-liquid flow and emulsion remain relatively unexplored, al- though they are of fundamental importance in optimiz- ing the operating conditions of these pumps. Hence, this study aims at investigating the performance degra- dation of a centrifugal pump under emulsion flow by combined means of analytical and computational fluid dynamic (CFD) models. The analytical approach is based on internal energy loss equations while the CFD approach models the emulsion as a continuous and ho- mogeneous single-phase fluid exhibiting shear thinning behavior. The results give a good insight into the per- formance degradation of such a system, especially at the best efficiency point (BEP).Item Numerical assessment of the hydrodynamic behavior of a volute centrifugal pump handling emulsion(MDPI, 2022) Achour, Lila; Specklin, Mathieu; Belaidi, Idir; Kouidri, SmaineAlthough emulsion pumping is a subject of growing interest, a detailed analysis of the fluid dynamic phenomena occurring inside these machines is still lacking. Several computational investigations have been conducted to study centrifugal pumps carrying emulsion by analyzing their overall performance, but no studies involved the rheological behavior of such fluids. The purpose of this study is to perform a computational analysis of the performance and flow characteristics of a centrifugal pump with volute handling emulsions and oil–water mixtures at different water cuts modeled as a shear-thinning non-Newtonian fluid. The studied pump consists of a five-bladed backward curved impeller and a volute and has a specific speed of 32 (metric units). The rheological properties of the mixtures studied were measured experimentally under a shear rate ranging from 1 s−1 to 3000 s−1 and were fitted to conventional Cross and Carreau effective viscosity models. Numerical results showed the flow topology in the pump is directly related to the viscosity plateau of the pseudoplastic behavior of emulsions. The viscosity plateau governs pump performance by influencing the loss mechanisms that occur within the pump. The larger the ν∞, the less recirculation loss the fluid experiences, and conversely, the smaller the value of ν0, the less friction loss the fluid experiencesItem Study of Ostwald-de Waele fluid flow in an elliptical annulus using the slot model and the CFD approach(Taylor & Francis, 2020) Ferroudji, Hicham; Hadjadj, A.; Rahman, M.A.; Hassan, I.; Maheshwari, P.; Odan, M.A.Among consequences that can be induced by a non-uniform distribution of the stress and other causes during the drilling process is the elliptical shape of the well and consideration of this effect would improve the accuracy of the drilling fluid hydrodynamics prediction. In the present work, the elliptical shape of the annular space is simplified to apply the slot model taking into account the rotation of the inner cylinder. Moreover, the Slot model results are compared with the experimental data, as well as, with the CFD outcomes where a reasonable concordance is observed, especially for low ratios of the major and minor semi-axis. Also, the CFD results are validated with the experimental data from the flow loop setup. We concluded that the increase of the major and minor semi-axis ratio of the elliptical annulus results in a linear increase of the Ostwald-de Waele frictional pressure loss in the laminar regime for all considered rotation speeds of the inner cylinder. In addition, the increase of the eccentricity from 0 to 0.75 has a positive effect where the frictional pressure loss is decreased by almost 28% for all rotation speeds for the elliptical annulus ((Formula presented.))Item CFD prediction of hydrogen passive autocatalytic recombiner performance under counter-current flow conditions(Elsevier, 2020) Halouane, Y.; Dehbi, A.Passive Autocatalytic Recombiners (PAR) are frequently used today as safety devices to mitigate hydrogen risk in confined spaces. The present study aims to investigate by CFD tools the PAR performance under potentially adverse counter-current flow conditions. Experimental data obtained from the THAI+ two-compartment facility are used to validate the numerical simulation. Counter-current flow is created by a fan in the larger vessel which produces a downward flow in the second vessel housing the PAR unit. In the simulation, the H2 reaction rate is computed by a correlation given by the PAR manufacturer, and hence no detailed chemistry is necessary. In agreement with test data, the simulation results show that PAR operation is not hindered by the imposed counter-current flow, although the plume exiting the PAR is somewhat compressed compared to that existing in quiescent atmospheres. It is also found that the computed parameters of interest (reaction rates, mean flow velocities, hydrogen PAR inlet/outlet concentration, temperature, pressure) agree well with the measured data. This confirms the usefulness of using CFD simulations to predict PAR behavior in complex flows and geometriesItem Flow simulation and performance analysis of a drilling turbine(the Academic Publication Council of Kuwait University, 2020) Sahnoune, Khaled; Benbrik, Abderahmane; Mansour, Ahmed Saeed Mohamed; Rekik, OussamaTurbodrills are axial hydraulic turbines which are used in drilling hydrocarbons in extreme conditions, possessing advantages over other drilling techniques with their high speed of rotation, and higher operating torques. In The present work, a numerical simulation of a Newtonian Drilling Mud flow was carried out through one stage of this turbine that has a stator and a rotor. The steady state mixing plane model was used for the simulations to take the rotation of the rotor into account besides the spatially averaged property fluxes of the flow. The turbulence K-ε model was used to consider the turbulence effects. Key performance parameters are calculated as a function of rotation speed and they are validated against the experimental data of the same model geometry in real operating conditions, a good agreement have been found between manufacturer power and torque data, and our simulation results for the same variables. Various flow fields are presented such as velocity and pressure, which had a great influence on the performance of the studied turbine. This will lead to choose the best parameters configuration of an optimal field operation.Item Predicting unsteady behavior of a small francis turbine at several operating points(Elsevier, 2018) Laouari, Ahmed; Ghenaiet, AdelItem Cooling enhancement of planar-balanced magnetron cathode(Springer, 2017) Salhi, M’hamed; Abaidia, Seddik-El-Hak; Mohamedi, Brahim; Laouar, Sofiane