RAZIK Benderradji

BRAHIMI Meryem

Etude numérique de la convection mixte dans une cavité à l'aide d’un nanofluide hybride soumise à l’action d’un champ MHD

Yahoui Nour

Étude numérique du transfert de chaleur par l’utilisation des nano-fluides dans un moteur Stirling

CHEBICHEB Majda , DIF Yasmine

Effet du nanofluide hybride Ag-CuO/eau rempli dans une cavité sur la convection naturelle. Caractéristique de transfert de chaleur.

HALILOU Rima

Convection mixte nanofluidique en cavité carrée ventilée. Approche Numérique.

benguezzou djouhaina , sehaim sohaib

Étude de la convection mixte dans une cavité en présence d’un Hybride et Nano-Fluide

NOUI Asma , BOUCHAREB Siham

Etude numérique de la convection naturelle dans une cavité différentiellement chauffée remplie de nano-fluides

ANIBA AMINA , REZZIG BOUTHEYNA

Étude numérique d’une tuyère convergente divergente, améliorations du système de propulsion et des performances.

FAID Hanane , CHERIEF Kalthoum

Etude numérique de la convection naturelle dans une cavité différentiellement chauffée remplie de nano-fluide.

ACHOUR Meriem , AIB Nour Elhouda

Etude numérique des interférences de choc dans les tuyères sur-détentes à choc interne

BENHAMADI Asma , LAIB Lahcen

Etude et réalisation d'un moteur stirling couplé à un concentrateur solaire

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Razika IHADDADENE , AMMAR Semane , Razik BENDERRADJI , Alhadj Rouache, ,(2025-10-30), Numerical investigation of collector diameter effects in solar chimeny systems,The First National Symposium on Structural and Materials Mechanics (SNMSM’25),M'sila, Algerie

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Razika IHADDADENE , AMMAR Semane , Razik BENDERRADJI , Alhadj Raouache, ,(2025-10-07), Numerical analysis of the impact of collector diameter on solar chimney performance,3rd International Workshop on Environmental Engineering,Sétif, Algerie

This study presents a comprehensive numerical investigation into steady-state mixed convection heat transfer within a square ventilated cavity containing a centrally positioned isothermal cold cylinder. The objective is to assess the combined effects of nanofluids and magnetic fields on thermal performance. The working fluids considered include pure water and water-based nanofluids enhanced with copper (Cu) and aluminium oxide (Al2O3) nanoparticles. Simulations were conducted across a range of Richardson numbers (0.1 < Ri < 100), Hartmann numbers (0 < Ha < 100), and nanoparticle volume fractions (0% < φ < 8%), using the finite volume method and the SIMPLER algorithm. Distinct from prior studies, this work bridges two gaps: (i) quantifying how high magnetic fields (Ha > 50) diminish nanoparticle-enhanced heat transfer and (ii) integrating artificial intelligence not only for prediction but also optimisation. Specifically, three machine learning models Decision Tree (DT), K-Nearest Neighbors (KNN), and a Deep Neural Network optimised via Genetic Algorithm (DNN-GA) were trained on 160 high-fidelity simulation datasets to estimate the average Nusselt number. Results demonstrated the DNN-GA’s superior accuracy (R² = 0.999, RMSE = 0.021) over DT (R² = 0.978) and KNN (R² = 0.921). Furthermore, five metaheuristic algorithms Queuing Search Algorithm (QSA), Barnacles Mating Optimiser (BMO), Search and Rescue (SAR), Gradient-Based Optimiser (GBO), and Manta Ray Foraging Optimisation (MRFO) were applied to maximise heat transfer. Optimisation identified Cu nanoparticles at Ri = 109.7, Ha = 9.0, and φ = 6% as optimal (Nu = 34.95), validated experimentally with 0.89% error. The findings confirm that increasing Ri and Ha enhances heat transfer efficiency (by 12–18%), while nanoparticle contribution declines (to 3–5%) at higher Ha. This work offers a dual contribution: advancing understanding of MHD nanofluid interactions in ventilated cavities and demonstrating a robust AI-driven framework for thermal system design.

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Razik BENDERRADJI , , (2025-08-15), Optimised heat exchange in a magnetised nanofluid-filled cavity using hybrid deep neural network and metaheuristic algorithms, Engineering Applications of Computational Fluid Mechanics, Vol:19, Issue:1, pages:22, Taylor & Francis Group.

FSW is a welding method that joins pieces of material by rotating a non-consumable pin at high speeds (RPM) while moving it along the weld joint. The combination of this rotation and movement generates heat through friction between the tool and the sheets, facilitating the welding process without the requirement for filler metal. Developed by the British Welding Institute (TWI) in 1991, FSW is celebrated for producing strong, reliable welds and is extensively used in industries such as automotive and aerospace. In these sectors, Brazilian Journal of Technology 2 ISSN: 2595-5748 Brazilian Journal of Technology, Curitiba, v.7, n.4, p. 01-22, 2024 aluminum alloys are essential due to their unique set of properties, making them highly suitable for FSW applications. In FSW, welding speed refers to the linear velocity at which the tool progresses along the joint line during the welding process. This parameter plays a pivotal role in controlling heat generation, material flow, and ultimately, the quality of the weld. The quantity of heat introduced to the plates directly influences the final weld quality, as well as the residual stresses and deformation observed in the workpieces. This research examines how different welding speeds affect temperature distribution, the width of the heataffected zone, and the Von Mises stress distribution in welded aluminum alloy 6061 sheets. The aim of this study is to gain a comprehensive understanding of how these factors interact, with the ultimate goal of contributing to the optimization of FSW parameters and improving weld quality. The analysis was performed using finite element method and ALTAIR software, providing valuable insight into the effects of welding speed variations.

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Razik BENDERRADJI , , (2024-12-16), Thermo-mechanical simulation of the effect of tool welding speed on butt-joint friction stir welding (FSW) of AA6061, Brazilian Journal of Technology, Vol:7, Issue:4, pages:01-22, Brazilian Journals Publicações de Periódicos e Editora Ltda

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Razik BENDERRADJI , ,(2024-11-22), Experimental analysis of temperature evolution in a solar chimney power plant,2nd International Conference on Trends in Advanced Research ICTAR 2024 November,Konya/Turkey

polycopie de cours pour les Master I et L3 : Physique Énergétique et Énergies Renouvelables

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RazikBENDERRADJI , ,(2024-11-04); Transferts thermique,M'sila,

L3 : Physique Énergétique et Énergies Renouvelables

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RazikBENDERRADJI , ,(2024-11-04); Travaux pratiques transferts thermique,m'sila,

The turbulent flow within Over-Expanded Nozzles is characterized by shock waves inducing unsteady separation of the boundary layer, which can exhibit both free and restricted detachment. This study investigates various physical phenomena encountered during the expansion regime, including supersonic jet formation, jet separation, adverse pressure gradients, shockwave interactions, turbulent boundary layers, compressible mixture layers, and large-scale turbulence. These complex phenomena significantly influence nozzle performance. Utilizing numerical simulations based on the resolution of Navier-Stokes equations via finite volume methods and employing the CFD-FASTRAN code, this research analyzes detachment characteristics, transition phenomena, and the predictive accuracy of different turbulence models. A test case from the ATAC project CNES-ONERA (Aerodynamics of Hoses and Back-bodies), is examined to elucidate the hysteresis phenomenon and asymmetrical configurations resulting from boundary layer detachment.

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Razik BENDERRADJI , , (2024-10-29), Numerical Simulation of the Hysteresis Phenomenon and Asymmetrical Configuration of Turbulent Gas Flow in an Over-Expanded Nozzle Flows, WSEAS TRANSACTIONS on FLUID MECHANICS, Vol:19, Issue:, pages:306-313, WSEAS.

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Razik BENDERRADJI , ,(2024-10-10), Rotational Speed Influence on Copper-Aluminum Friction Welding,5th International Conference on Innovative Academic Studies,Konya/Turkey.

This study presents a parametric numerical investigation of laminar natural convection and heat transfer in a cavity with opposite sinusoidal wavy walls, filled with hybrid Ag-CuO/water nanofluid. The vertical walls of the cavity are maintained at distinct hot and cold temperatures, while the upper and lower boundaries are thermally insulated. The study examines the effects of key factors, including the sinusoidal wall shape, nanoparticle volume fractions (0% ≤ 𝜙 ≤ 6%), and Rayleigh numbers (10³ ≤ Ra ≤ 10⁶). A finite volume discretization method, using the SIMPLE algorithm, is employed to solve the governing equations, with Ansys Fluent software ensuring quadratic accuracy. Mesh independence is confirmed with a 200 × 200 mesh, and code validation is performed through comparison with previous studies. Results indicate that increasing the nanoparticle volume fraction enhances heat transfer within the cavity. Additionally, the Rayleigh number significantly influences the heat transfer mode, with higher Ra values promoting stronger convective activity. Detailed analysis of temperature and velocity profiles, along with Nusselt number variations, highlights the impact of nanoparticle concentrations and Rayleigh numbers. The wavy wall geometry improves fluid mixing and thermal boundary layer interaction, leading to enhanced heat dissipation. These findings underscore the potential of hybrid nanofluids and wavy wall designs to optimize heat transfer in engineering systems.

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Razik BENDERRADJI , , (2024-10-01), Characteristics and Efficiency of Heat Transfer for Natural Convection by Ag-CuO/H2O Hybrid Nanofluid Inside a Square Cavity with Corrugated Walls, Science, Engineering and Technology, Vol:4, Issue:2, pages:101-114, O.D. IMS Vogosca

In this numerical study, the focus was on analyzing the heat transfer by mixed convection in a ventilated cavity filled with a hybrid nano-fluid. The hybrid nano-fluid consists of nano-particles (copper (Cu) and alumina (Al2O3)) dispersed in a base fluid (water). The volume fraction of nano-particles is 4 %. The cavity housed a cold cylinder at its center and incorporated two gates (orifices) for the influx and efflux of the flow., with a fixed Reynolds number (Re) and varying Richardson numbers (Ri) set at 0.1, 1, 10, and 100. The cavity was subjected to isothermal heating by a heat source on the lower wall to maintain a constant temperature, while the remaining walls were kept adiabatic. The ventilated cavity is subjected to mixed convection, where both natural convection and forced convection effects are considered. The governing equations for the stationary laminar flow were solved numerically using the finite volume method. The numerical results revealed the significant impact of Ri on heat transfer within the ventilated cavity. Consequently, the heat transfer rate (expressed by Nusselt number Nu) demonstrated an upward trend with increasing Ri values. Overall, the results of this study were provide valuable insights for understanding the behavior and performance of systems that utilize hybrid nano-fluids in applications such as microelectronics cooling, heat exchangers, and energy storage devices.

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Razik BENDERRADJI , ,(2024-09-25), Analysis of Heat Transfer by Mixed Convection in a Ventilated Cavity Filled with Hybrid Nano-Fluid: A Numerical Approach,6 thInternational Conference on Applied Engineering and Natural Sciences,Konya, Turkey

A numerical study was conducted to investigate mixed convection in a square ventilated cavity with a central cooling cylinder, aimed at evaluating heat exchange. The study used pure water and mixtures with Cu and Al₂O₃ nanoparticles. The analysis covered a wide range of Richardson numbers (0.1 < Ri < 100), Hartmann numbers (0 < Ha < 100), and nanoparticle volume fractions (0% < φ < 8%), under the influence of a uniform external magnetic field. The governing non-dimensional equations and boundary conditions were solved using the finite volume method and the SIMPLER algorithm.

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Razik BENDERRADJI , ,(2024-09-25), Statistical Analysis and Numerical Study for the Optimization of Magnetohydrodynamic (MHD) Mixed Convection in Ventilated Cavities Using Nanofluids,6 th International Conference on Applied Engineering and Natural Sciences,Konya, Turkey

In contemporary power engineering and microelectronics, the efciency of cooling systems is of crucial importance. To meet this requirement, specialized approaches and the use of nanofuids are employed to improve the heat dissipation of heat-generating components. This study presents a methodology based on a numerical simulation investigation and statistical analysis using the Response Surface Methodology (RSM) to estimate the average Nusselt number (Nuavg) associated with mixed convection in a ventilated cavity. The study considered pure water and mixtures of nanoparticles (Cu, Ag, and TiO2) as heat transfer fuids, exploring various values of the Richardson number (0.1 to 100) and volume fractions (0 to 8%). Analysis of Variance (ANOVA) and the quadratic mathematical model developed by RSM efectively predicted the results of the numerical simulation with a coefcient of determination R2 close to 1. The results obtained from the 3D curves of the RSM show that the average Nusselt number (Nuavg) increases signifcantly with the Richardson number. Conversely, an increase in the volumetric fraction leads to a slight decrease in Nuavg. Furthermore, it is observed that the agent (Ag) generates higher Nuavg values compared to other materials such as copper (Cu) and TiO2. Combining the RSM method with the desirability function (DF) allows for achieving the optimal average Nusselt number (Nuavg). Validation of the values proposed by the DF and those obtained by simulation shows a very small relative error, less than 0.13%.

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Razik BENDERRADJI , , (2024-09-19), A numerical study and statistical approach of the impact of nanofluids on mixed convection in a ventilated cavity, The International Journal of Advanced Manufacturing Technology, Vol:134, Issue:11, pages:5281–5300, Springer Nature

This research presents the results of a numerical study on mixed convection in a ventilated cavity with a central cold block of varying shapes. The direction of the forced flow of Ag/water nanofluid is perpendicular to the transverse axis (y) of the central cold block. Mixed convection is induced by cooling at the entrance of the ventilated cavity and uniformly heating its bottom wall. The governing equations for the flow of an incompressible Newtonian nanofluid are assumed to be two-dimensional, steady, and laminar. The finite volume method is employed for numerical simulations. A series of calculations are conducted to investigate the effects of key influencing factors: Reynolds number (Re = 100), Richardson number (Ri = 1), and nanoparticle volume fractions (0 ≤ ∅ ≤ 8%) on the enhancement of heat transfer. The impact of four different geometric shapes of the cold obstacle (circular, square, triangular, and elliptical) on fluid flow and heat transfer rate is also explored. The results indicate that an increase in nanoparticle volume fraction enhances the heat exchange rate in the cavity only when the geometric shape of the cold obstacle is circular. This is followed by square and triangular shapes, which approximately yield concordant results, and then the elliptical shape.

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Razik BENDERRADJI , , (2024-04-01), Mixed Convection of an Ag/Water Nanofluid in a Ventilated Square Cavity Containing Cold Blocks of Different Shapes, WSEAS Transactions on Heat and Mass Transfer, Vol:19, Issue:, pages:33-40, wseas

A parametric numerical study is conducted on laminar natural convection and heat transfer in a cavity with opposing undulated walls saturated with a hybrid Ag-CuO/water nanofluid. The two vertical walls of the sinusoidally undulated cavity are maintained at hot and cold temperatures, while the upper and lower walls are thermally insulated. The investigation examines the effects of relevant parameters such as the sinusoidally undulated geometry of the walls for different volumetric fractions of nanoparticles (0% ≤𝝋≤6%) and Rayleigh numbers (103 ≤ Ra ≤ 106) Thefinite-volumee discretization method is employed to solve the system of governing equations. The results indicate that an increase in the volumetric fraction of nanoparticles enhances the heat exchange rate in the cavity. Additionally, the Rayleigh number, with a significant increase in surface area, strongly influences the dominant heat transfer mode in the cavity. Furthermore, an increase in the number of wall undulations leads to a reduction in the heat transferrate. Type or paste your abstract here as prescribed by the journal’s instructions for authors. Type or paste your abstract here as prescribed by the journal’s instructions for authors. Type or paste your abstract here.

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Razik BENDERRADJI , ,(2024-01-29), The Effect of corrugation on the behavior of nanoparticles and the heat transfer of the natural convection of an Ag-CuO/Water hybrid nanofluid in a square cavity with corrugated walls,3rd International Congress on Scientific Research,ankar, turkiye

Bienvenue dans ce polycopié de cours sur les transferts thermiques et les travaux pratiques associés. Ce document a été conçu pour accompagner votre apprentissage dans le domaine fascinant et crucial du transfert de chaleur. Il vise à fournir une base solide de connaissances théoriques ainsi que des applications pratiques pour renforcer votre compréhension. Objectifs du Polycopié: 1. Compréhension Théorique : Ce polycopié présente les concepts fondamentaux du transfert de chaleur, couvrant les modes de conduction, convection et rayonnement. Les principes théoriques sont expliqués de manière claire et concise pour faciliter votre compréhension. 2. Applications Pratiques : Les travaux pratiques inclus dans ce document offrent l'opportunité d'appliquer les connaissances théoriques à des situations réelles. Ces exercices visent à renforcer vos compétences pratiques dans l'analyse et la résolution de problèmes liés au transfert de chaleur. 3. Guides d'Étude : Vous trouverez des directives et des conseils pour maximiser votre apprentissage. Les travaux pratiques sont accompagnés d'instructions détaillées pour vous guider tout au long du processus.

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RazikBENDERRADJI , ,(2024-01-21); POLYCOPIÉ DE COURS TRANSFERTS THERMIQUE Et TRAVAUX PRATIQUES,university of m'sila,

This study numerically examines laminar natural convection in a sinusoidal wavy cavity, filled with pure water and Ag-CuO/Water hybrid nanofluid, which is a new advanced nanofluid with two types of nanoparticle materials. The two vertical walls of the enclosure with a sinusoidal undulating geometry are maintained at hot and cold temperatures respectively, while the upper and lower walls are thermally insulated. The present investigation examined the effects of relevant parameters such as sinusoidal wavy wall geometry, for different nanoparticle volume fractions (0% volume concentration ≤𝜙≤6%) and Rayleigh numbers (103 ≤ Ra ≤ 106). The finite volume discretization method is used to solve all the governing equations. The results show that the heat transfer rate inside the corrugated enclosure increases by decreasing the amplitude of the corrugated surface. Additionally, increasing the number of corrugations leads to improving the heat transfer rate. It is also found that by increasing the volume fraction of nanoparticles and the Rayleigh number, the heat transfer rate increases.

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Razik BENDERRADJI , brahimi meryem, ,(2023-12-02), Effect of Ag-CuO/water hybrid nanofluid filled in a cavity on natural convection. Heat transfer characteristic.,THE 1ST NATIONAL CONFERENCE ON PHYSICS AND IT’S APPLICATIONS BOUSAADA, 2nd December 2023,BOUSAADA

The present study is concerned with both the development of the supersonicflow turbulent boundary layer on a flat plate, the distance required to invade the entiresection of the plate, and the effects of the size of the zone of interaction on thedevelopment of the same boundary layer. The increase in the force of the interaction is anincrease in the size of the zones of interactions leading to the formation of a recirculatingbubble which is an area of sign ificant pressure drops. For th is reason, one can decreaseand then increase the Mach number to see a Mach reflection that explains the impact ofthe strong incident shock wave with the boundar y layer. The increase and decrease of theMach number caused the occurrence of a transition in regular reflection (RR)interactions, Mach reflection (MR), which is represented by the iso contours of the fieldsof density. These studies are well in agreement with the trial which was presented byDélery et al. (2009). Another contribution and investigations of the phenomenon of shockwave / turbulent boundary layer interaction were given. The model used in this study isthe kw-SST model, considered to be the mo st suitable for this kind of problem, withspecial treatment of the zone near the wa ll. Numerical simulations were made usingFLUENT software. (25) (PDF) Etude numérique de transition RR / MR dans l’interaction onde de choc / choc de compression. Available from: https://www.researchgate.net/publication/376328701_Etude_numerique_de_transition_RR_MR_dans_l'interaction_onde_de_choc_choc_de_compression#fullTextFileContent [accessed Jan 28 2024].

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Razik BENDERRADJI , gouidmi hamza, Abdelhadi Beghidja, , (2023-10-01), Etude numérique de transition RR / MR dans l’interaction onde de choc / choc de compression, Revue des Energies Renouvelables, Vol:19, Issue:4, pages:595 - 604, CDER

This study numerically investigates laminar natural convection in a sinusoidal corrugated cavity, filled with pure water and Ag-CuO/Water hybrid nanofluid, which is a new advanced nanofluid with two types of nanoparticulate materials. In this work, the two vertical walls of the enclosure with a sinusoidal undulating geometry are maintained at hot and cold temperatures respectively, while the upper and lower walls are thermally insulated. The present investigation examined the effects of relevant parameters such as the sinusoidal undulating geometry of the walls, for different volume fractions of nanoparticles (0% volume concentration ≤𝜙≤6%) and Rayleigh numbers (103 ≤ Ra ≤ 106). The finite volume discretization method is used to solve the set of governing equations. The results show that the rate of heat transfer inside the corrugated enclosure increases by decreasing the amplitude of the corrugated surface. In addition, increasing the number of corrugations leads to improved heat transfer rate. It is also found that by increasing the volume fraction of the nanoparticles and the Rayleigh number, the rate of heat transfer increases.

Citation

Razik BENDERRADJI , ,(2023-06-24), Numerical modeling of natural convection heat transfer performance in a sinusoidal corrugated wall enclosure by Employing Hybrid Nanofluid,6. INTERNATIONAL PALANDOKEN SCIENTIFIC STUDIES CONGRESS 24-25 JUNE 2023,ERZURUM / TURKEY

In this work, a numerical study of stationary laminar mixed convection in a ventilated square cavity has been presented. The cavity is filled with different nanofluids and contains two gates (ports) to enter and exit the flow. The straight vertical wall is maintained at a warm temperature, while the other walls are considered adiabatic. The equations governing flow and heat transfer have been solved by the finite volume method using a second-order centered Upwind scheme. Numerical simulations are carried out in the case of pure water fluid, and mixtures of this basic fluid and nanoparticles (Ag and Cu), for a number of Ri varying from (0.04 to 4) and a volume fraction of the nanoparticles between (0% and 10%). The study presented in this work is devoted to a dynamic study in which the Grashof number is fixed at 104, and the Reynolds number is varied. The numerical results obtained show that the heat transfer increases with the increase in the volume fraction also that the enhancement of the product of entropy generation and heat transfer increases considerably with the increase in the Reynolds number. The most effective nanoparticles for increasing the heat exchange rate are Ag. The latter are characterized by a large local Nusselt number, that is to say a very good heat transfer compared to that of metallic Cu nanoparticles.

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Razik BENDERRADJI , ,(2022), INFLUENCE DES NOMBRES DE REYNOLDS ET DE GRASHOF SUR LA CONVECTION MIXTE DANS UNE CAVITE CARREE CONTENANT DES PORTES D’ENTREE ET DE SORTIE DE NANOFLUIDE,INTERNATIONAL MEDITERRANEAN CONGRESS,Mersin, Türkiye

A numerical simulation of stationary laminar flow by free convection in a two-dimensional cavity filled with different nanofluids (nanofluids and hybrid nanofluids) has been carried out. The square cavity is isothermally heated from below. Indeed, 1/3 of the surface of the lower wall is heated by a heat source (the source is to maintain the lower wall at a constant temperature), the two vertical side walls are cooled and the upper wall is maintained adiabatic. The equations that govern the flow have been solved numerically via the finite volume method using a Power-Low scheme. Numerical simulations are carried out in the case of pure water fluid, and mixtures of this basic fluid and nanoparticles (Ag), (Cu) and hybrid nanoparticle (Ag-CuO), for a Rayleigh number varying from 103 to 105, and a volume fraction of the nanoparticles of between (0% and %4). To deeply examine the effects of relevant parameters on hydrodynamic flow and heat transfer in our setup. The results obtained show that the heat transfer increases with increasing volume fraction and Rayleigh number. Thus the heat transfer rate (Nu) increases with increasing Ra. We will divide this study into two main parts: • Effect of concentration of nanoparticles. • Effect of types of nanoparticles.

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Razik BENDERRADJI , ,(2022), EFFECT OF THE HYBRID NANOFLUID (AG–CUO/WATER) ON THE HEAT TRANSFER CHARACTERISTICS BY NATURAL CONVECTION IN A SQUARE CAVITY: NUMERICAL STUDY,THE 1ST INTERNATIONAL CONFERENCE ON RENEWABLE MATERIALS AND ENERGIES ICRME2022,OUARGLA-ALGERIA

In this work, a numerical study of stationary laminar mixed convection in a ventilated square cavity has been presented. The cavity is filled with different nanofluids and contains two gates (ports) to enter and exit the flow. The straight vertical wall is maintained at a warm temperature, while the other walls are considered adiabatic. The equations governing flow and heat transfer have been solved by the finite volume method using a second-order centered Upwind scheme. Numerical simulations are carried out in the case of pure water fluid, and mixtures of this basic fluid and nanoparticles (Ag and Cu), for a number of Ri varying from (0.04 to 4) and a volume fraction of the nanoparticles between (0% and 10%). The study presented in this work is devoted to a dynamic study in which the Grashof number is fixed at 104, and the Reynolds number is varied. The numerical results obtained show that the heat transfer increases with the increase in the volume fraction also that the enhancement of the product of entropy generation and heat transfer increases considerably with the increase in the Reynolds number. The most effective nanoparticles for increasing the heat exchange rate are Ag. The latter are characterized by a large local Nusselt number, that is to say a very good heat transfer compared to that of metallic Cu nanoparticles.

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Razik BENDERRADJI , ,(2022), NUMERICAL STUDY OF HEAT TRANSFER BY MIXED CONVECTION IN A CAVITY FILLED WITH NANOFLUID,THE 1ST INTERNATIONAL CONFERENCE ON RENEWABLE MATERIALS AND ENERGIES ICRME2022,OUARGLA-ALGERIA

In this work, we carried out a numerical study of the stationary laminar flow by mixed convection in a ventilated two-dimensional cavity containing a cold cylinder in the center of the latter. The cavity is filled with different hybrid nano-fluids, (Water/Ag-TiO2) and (Water/Al2O3-TiO2)). The cavity containing two gates (Orifices) of entry and exit of the flow, for a Reynolds number (Re) fixed so that the Richardson number takes the values: Ri = 0.1, 1, 10 and 100, and a volume fraction of the nanoparticles comprised between (0% and 8%). The square cavity is heated isothermally by the surface of the lower wall by a heat source (The source is to maintain the lower wall at constant temperature), the other walls are maintained adiabatic. The equations, which govern the flow, have been solved numerically using the finite volume method. The results obtained show that the heat transfer increases with the increase in the volume fraction and the Richardson number. Thus the heat transfer rate (Nu) increases with the increase in Ri.

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Razik BENDERRADJI , ,(2022), NUMERICAL STUDY OF HEAT TRANSFER BY MIXED CONVECTION IN A VENTILATEDCAVITY FILLED WITH HYBRID NANO-FLUID,THE 1ST INTERNATIONAL CONFERENCE ON RENEWABLE MATERIALS AND ENERGIES ICRME2022,OUARGLA-ALGERIA

In this work, we carried out a numerical study of the stationary laminar flow by mixed convection in a ventilated two-dimensional cavity containing a cold cylinder in the center of the latter. The cavity is filled with different hybrid nano-fluids, (Water/Ag-TiO2) and (Water/Al2O3-TiO2)). The cavity containing two gates (Orifices) of entry and exit of the flow, for a Reynolds number (Re) fixed so that the Richardson number takes the values: Ri = 0.1, 1, 10 and 100, and a volume fraction of the nanoparticles comprised between (0% and 8%). The square cavity is heated isothermally by the surface of the lower wall by a heat source (The source is to maintain the lower wall at constant temperature), the other walls are maintained adiabatic. The equations, which govern the flow, have been solved numerically using the finite volume method. The results obtained show that the heat transfer increases with the increase in the volume fraction and the Richardson number. Thus the heat transfer rate (Nu) increases with the increase in Ri.

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Fares KHALFALLAH , Razik BENDERRADJI , Meryem Brahimi , RAOUACHE El Hadj, ,(2022), NUMERICAL STUDY OF HEAT TRANSFER BY MIXED CONVECTION IN A VENTILATED CAVITY FILLED WITH HYBRID NANO-FLUID,1ST INTERNATIONAL CONFERENCE ON RENEWABLE MATERIALS AND ENERGIES ICRME2022,OUARGLA-ALGERIA

La mécanique des fluides numérique (MFN), plus souvent désignée par le terme anglais computational fluid dynamics (CFD), consiste à étudier les mouvements d'un fluide, ou leurs effets, par la résolution numérique des équations régissant le fluide. En fonction des approximations choisies, qui sont en général le résultat d'un compromis en termes de besoins de représentation physique par rapport aux ressources de calcul ou de modélisation disponibles, les équations résolues peuvent être les équations d'Euler, les équations de Navier-Stokes, etc.

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Razik BENDERRADJI , ,(2022), Dynamique des fluides numérique,Journée doctorale en physique,M'sila

The flow in an Over-Expanded Nozzle is subjected to shock waves leading to the unsteady separation of the boundary layer. Free detachment may be followed by a restricted detachment. During the expansion regime in propellant nozzles, several physical phenomena are encountered: supersonic jet, jet separation, adverse pressure gradient, shock wave, turbulent boundary layer, highly compressible mixture layer, return flow, large scale turbulence. These very complex phenomena can considerably affect the performance of the nozzle.The numerical investigation was performed by the CFD-FASTRAN search code, using the k-w SST model as the turbulence model. The calculation is performed by solving the Navier-Stokes equations of two-dimensional compressible turbulent flow. It is based on the study of the fluidic vectorization phenomenon of the thrust of a double-injection convergent-divergent supersonic conical nozzle. The study is based on the effect of the ratio of NPR pressures with SPR = 1 on the overall structure of shock waves. The calculation is highlighting the behavior of a flow that has not neglected. In particular, the appearance of the separation zone formed by the fluid jet and the deflection of the main jet cause separation shocks.

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Razik BENDERRADJI , , (2020), Effect of the fluidic injection on the flow of a converging-diverging conical nozzle, International Journal of Energetica (IJECA), Vol:5, Issue:1, pages:07-13, Al Manahil Association (Algeria).

L’utilisation de l’énergie solaire à travers un collecteur parabolique (concentrateur solaire parabolique) promet une énergie verte limitée telle que la production électrique. Une étude du capteur parabolique solaire a été réalisée sur la géométrie et la distribution des flux dans la région focale. Le diamètre de la parabole est un paramètre important pour déterminer le diamètre d'imagerie et non imageur du rayonnement de flux au point focal. La géométrie a été simulée à l'aide d’un logiciel open source (Tonatiuh) qui permet de modéliser une antenne parabolique et de simuler son comportement optique. La distribution du flux a ensuite été tabulée sur le graphique coordonné pour obtenir le diamètre. Les diamètres d'imagerie se situent entre 4 m et plus, tandis que les valeurs de diamètre sans formation d'image se situent entre 1 et 3 m. Cela montre que le paramètre optimal de la parabole est important pour obtenir une haute intensité de mise au point.

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Razik BENDERRADJI , ,(2020), Simulation de l’Efficacité Géométrique d’un Concentrateur Solaire Parabolique sur la Distribution du Flux,1ère Conférence Nationale sur la Transition Energétique en Algérie (CNTEA 1 – 2020) Université Mohamed BOUDIAF de M’sila,,M'sila

L’échange de chaleur par convection mixte dans une cavité 2D d’un écoulement incompressible laminaire, est étudié numériquement. Cette étude a permis de prédire le comportement de la structure de l’écoulement entre une structure multicellulaire dominé par une convection naturelle lorsque le nombre de Reynolds est faible, et une structure multicellulaire dominé par une convection forcée lorsque le nombre de Reynolds est élevé. En premier lieu on fait fixer le nombre de Grashof pour le nombre de Reynolds variable. En deuxième lieu on fait varier le nombre de Grashof pour lesquels le nombre de Reynolds est maintenu fixe. Les résultats obtenus donnent une claire comparaison avec ceux trouvés dans la littérature.

Citation

Razik BENDERRADJI , ,(2020), Etude Numérique de la Convection Mixte dans une Cavité,1ère Conférence Nationale sur la Transition Energétique en Algérie (CNTEA 1 – 2020) Université Mohamed BOUDIAF de M’sila,,M'sila

This study provides a 3D numerical simulation of two-phase flow in upward vertical annuli pipe using the Fluent CFD commercial code. The condition of two-phase flow was simulated with the Volume of Fluid (VOF) model, taking into consideration turbulence effects using the k-e model. The internal and external diameters of the pipe are DT=12.7 mm, DC=38.1 mm, respectively and length L=16 m. Numerical results were obtained for various values of air velocity, Ug at fixed water velocity (Ul =0.14 m/s). In this numerical simulation, we have identified global flux structures and their transition regimes, such as the size and shape of bubbles, slug and their zigzag and coalescence phenomena. These flow regimes have been clearly influenced by the air velocity. The results obtained have been validated and are consistent with those experimentally reported

Citation

Razik BENDERRADJI , , (2019), Numerical Study of Upward Vertical Two-Phase Flow Through an Annulus Concentric Pipe, jJournal of Advanced Research in Fluid Mechanics and Thermal Sciences, Vol:58, Issue:2, pages:19, Akademia Baru Publishing

Flow around a finite end cylinder mounted vertically on a flat plate and thermally heated is simulated numerically by the Large-Scale Simulation (LES) approach. The flow is in subcritical regime circulate with a velocity U∞=0.54m/s corresponding a Reynolds number ReD=2.2x104 . The boundary condition of Neumann is imposed on the surface of the cylinder, which is reflected by a density of the heat flux is = 600W/m2 , for an aspect ratio H/D=5.This simulation induces a complex structure of the flow behind the cylinder, in particular the appearance of vortices and recirculation zones ahead and behind it. The results obtained give a clear comparison with those found experimentally and numerically of Guillermo PalauSalvador et al. [2], that were carried out its work in the case of adiabatic flow.

Citation

Razik BENDERRADJI , , (2019), Numerical study a flow around a heated finite cylinder and mounted vertically on a flat plate, WSEAS TRANSACTIONS on HEAT and MASS TRANSFER, Vol:14, Issue:, pages:12, wseas

Les transferts thermiques sont une science clé de l’énergie. On appelle chaleur l'échange d'énergie qu'il faut ajouter au travail reçu pour obtenir l'échange total d’énergie, et encore « la chaleur, comme le travail, n'est pas une énergie mais un transfert d'énergie ». Destiné en priorité aux étudiants en LMD et aux élèves ingénieurs, ce polycopié aborde les principaux modes de transferts d’énergie: la conduction, le rayonnement et la convection. Ces phénomènes très différents, mais pouvant interagir, doivent être connus de l’étudiant qui sera confronté un jour ou l’autre à un problème de transfert thermique. Il trouvera dans cette polycopie de nombreuses applications concrètes. Dans ce polycopié, la priorité est donnée à la compréhension physique des phénomènes et à l’apprentissage de la modélisation physique. Le but de ces travaux pratiques est d’illustrer une partie de ce que vous voyez dans le cours de transfert thermique, d’une part. D’autre part, ces travaux pratiques permettent de vous familiariser avec les méthodes de mesures et de détermination des différents coefficients de transfert thermique. Enfin, le travail demandé va vous incitera à dépouiller et analyser des données expérimentales, à discuter les résultats obtenus et à rédiger des comptes rendus techniques. Ces trois activités forment l’essentiel de ce que la majorité des étudiants sont appelés à faire le long de leurs carrières. Les comptes rendus sont le véhicule de transmission de vos réflexions, observations et solutions. Votre capacité à composer des rapports clairs et concis augmentera votre crédibilité et propulsera votre réussite. En effet, les résultats les plus intéressants ne peuvent intéresser le lecteur (votre patron ou votre client) que lorsque celui-ci arrive à saisir ce que vous lui présentez, sans s’ennuyer et abandonner la lecture. La capacité de préparer de bons comptes rendus s’apprend par la pratique. C’est la raison pour la quelle on exige un compte rendu bien rédigé. Dans tout travail expérimental, vous devez estimer l’incertitude des paramètres mesurés ou calculés à partir de mesures directes. Le polycopié est structuré en cinq TP. Dans la première partie, nous présenterons tout d’abord des généralités sur le transfert thermique, et quelques notions de base de calcul. La seconde partie présente les cinq travaux pratique, en détails de chacune.

Citation

RazikBENDERRADJI , ,(2019); travaux pratiques transfert thermique,université Mohamed boudiaf - M'sila,

In this work, we present a numerical study of mixed convection heat exchange in a cubic cavity of a laminar three-dimensional (3D) incompressible flow. This study predicted the behavior of the flow structure between Multi clear structure dominated by natural convection when the Reynolds number is small, and a Multi clear structure dominated by forced convection when the Reynolds number is high. First, we fix the Grashof number for the variable Reynolds number. Second, we vary the number of Grashof for which the Reynolds number is kept fixed. The results obtained give a clear comparison with those found in the literature it examines and explains the thermal and dynamic characteristics of the flow.

Citation

Razik BENDERRADJI , Djedid TALOUB , Hamza Gouidmi, Abdelhadi Beghidja, , (2018), Numerical study three-dimensional of mixed convection in a cavity: Influence of Reynolds and Grashof numbers, Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, Vol:51, Issue:1, pages:42-52, www.akademiabaru.com/arfmts.html

Dans l'optique de la production d'électricité, l'énergie solaire est une source d'énergie propre et inépuisable. Actuellement les technologies de concentration solaire sont celles qui présentent le plus de possibilités pour une exploitation commerciale. Cette énergie peut être transformée en chaleur à haute température, par concentration de rayonnement solaire. Cette opération est réalisée à l’aide de capteurs appelés concentrateurs solaires. Les systèmes solaires à concentration offrent la possibilité de produire de l’électricité à partir de l’énergie solaire, Parmi ce type de concentrateurs, il y a les concentrateurs solaires paraboliques. Ces systèmes comportent en général une surface réfléchissante sous forme parabolique destinée à concentrer l’énergie solaire sur une surface absorbante. Dans ce travail de recherche une étude du capteur parabolique solaire a été réalisée sur la géométrie et la distribution des flux dans la région focale. Le diamètre de la parabole est un paramètre important pour déterminer la quantité du rayonnement de flux au point focal. La géométrie a été simulée à l'aide d’un logiciel open source (Tonatiuh) qui permet de modéliser une antenne parabolique et de simuler son comportement optique. La distribution du flux a ensuite été tabulée sur le graphique coordonné pour obtenir le diamètre.

Citation

Razik BENDERRADJI , ,(2018), Effet de Diamètre d’un Concentrateur Solaire Parabolique Sur la Distribution du Flux,International Symposium on Mechatronics and Renewable Energies,El-Oued-ALGERIE-

Cette étude porte à la simulation numérique d'écoulement diphasique vertical ascendant dans une conduite annulaire en utilisant le code de calcul commercial Fluent. La conduite est de diamètre interne DT=12.7 mm et externe DC=38.1 mm et de longueur L=16 m, est la même que celle utilisée par Das et al. Cette étude est effectuée pour une vitesse du gaz variable et à une vitesse de liquide constante égale à 0.14m/s. Les régimes à bulles, à poche (ou à bouchons de liquide), à forte coalescence et annulaire sont observés et tracés par les champs des fractions volumiques de l'air. Les résultats obtenus sont validés et conformes avec ceux trouvés par de Das et al(1999).

Citation

Razik BENDERRADJI , ,(2018), Étude numérique d’écoulement diphasique co-courant ascendant dans une conduite annulaire verticale et concentrique,International Symposium on Mechatronics and Renewable Energies,El-Oued-ALGERIE-

Envisager de rendre compte de l’ensemble des réalités de la construction mécanique du XXIe, c’est considérer d’emblée le caractère industriel d’une activité incluant les technologies les plus diverses, de l'électricité à l'informatique, et recouvrant les besoins de la construction de véhicules terrestres, aériens, spatiaux, ainsi que les machines permettant de construire ces machines. Cependant, la construction mécanique reste au cœur de l’industrie, tant d’un point de vue historique (jusqu’aux années 1950, la conception de produits industriels est essentiellement perçue au travers de la « mécanique ») que d’un point de vue structurel (si diverses soient les technologies, la conception d’un produit industriel restera toujours tributaire de considérations liées à la résistance mécanique). Cette polycopie est un outil destiné aux professionnels (en activité ou en formation). Il permettra à chacun de mener à bien les projets de construction mécanique ; car pour choisir et assembler les différents composants, le technicien ou futur technicien sera aidé par l’analyse des fonctions remplies par ces composants, les bases des calculs à entreprendre, les conditions d’emplois, voire pour certains les indications de prix contient. Il se situe dans le cadre d’une pédagogie active par laquelle l’apprenant devient de plus en plus autonome, recherchant lui-même les informations et les connaissances dont il a besoin pour résoudre les problèmes qui se posent et mener à bien les réalisations qui lui sont demandées. Le polycopié est structuré en neuf chapitres. Dans le premier chapitre, nous présenterons tout d’abord des généralités sur le domaine de la construction mécanique, quelques notions de base de calcul RDM. Le second chapitre présent les assemblages mécanique dans la construction. Le troisième chapitre est consacré à l’emmanchement et frettage. Le quatrième chapitre présent les roulements, principe de calcule de la durée de vie des roulements, types de montage ansai que la méthode de désignation. Dans le cinquième chapitre on a traite les problème de transmission et transformation du mouvement, les déférents méthodes, et les rapports de transmission. Le sixième chapitre est consacré pour traité en détail les engrenages, c’est un complément de la chapitre précédent.

Citation

RazikBENDERRADJI , ,(2018); Eléments de machines,Université M'Hamed BOUGARA de Boumerdès,

Quand une onde de choc oblique vient frapper une paroi plane, deux types de réflexions sont possibles. Suivant l'inclinaison relative des chocs par rapport à la direction de l'écoulement amont, on obtient, soit une réflexion régulière (RR), soit une réflexion de Mach (MR). A des nombres de Mach supérieurs à 2, 2, il existe une gamme d'angles d'incidence pour lesquels ces deux types de réflexions sont conjointement possibles. C'est le domaine de solutions duales, qui a conduit à l'hypothèse de l'existence d'un effet d'hystérésis dans la transition RR-MR. Le but d’est de retrouver numériquement le phénomène d’hystérésis observé lors des études expérimentales dans l’interférence des ondes de choc, plus particulièrement les interactions régulières et de Mach. Il est alors question de traiter ce problème par une étude numérique conçu sur le principe de schéma de capture de choc

Citation

Razik BENDERRADJI , ,(2018), Les écoulements compressibles,les interférences des ondes de chocs et phénomène d'hystérésis,Ecole nationale d'ingénieur de Sfax (ENIS) tunisiens

L’objectif de ce travail s’articule d’une part sur la formation de couches de galvanisation par voie chimique (immersion) qui est la méthode la plus simple et d’autre part sur la caractérisation des couches élaborées tant de vue physico-chimique que mécanique. Aux cours de l’immersion chimique à chaud de substrats d’acier dans le bain de zinc lors de procédé de galvanisation, des composés intermétalliques (Fe-Zn) se forment et présentent des propriétés très recherchées dans l’industrie.

Citation

Leila BECHANE , Razik BENDERRADJI , ,(2007-05-08), Effet de temps de traitement (immersion) sur la formation des couches de galvanisation,deuxième journées de la physique et de ces applications (JPA-2007),l’Université Ibn-khaldoun, Tiaret.