Communications Internationales

Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/11

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Author: search.filters.author.Belaidi, Idir

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Now showing 1 - 10 of 21
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    Comparative Assessment of Non-newtonian Single-Phase and Two-Phase Approaches for Numerical Studies of Centrifugal Pumps Handling Emulsion
    (Springer Nature, 2024) Achour, Lila; Specklin, Mathieu; Asuaje, Miguel; Kouidri, Smaine; Belaidi, Idir
    Computational Fluid Dynamics is commonly employed to assess the effect of oil-water emulsions on pump performance, usually using two-phase models. However, these models often neglect the emulsion’s non-Newtonian behavior, despite its known experimental significance in enhancing pump performance. This study attempts to evaluate both single-phase non-Newtonian and two-phase approaches to model emulsion flow within centrifugal pumps. The non-Newtonian single-phase and several two-phase models are evaluated by comparing the predicted pump heads with experimental data of a multistage pump from the literature. The findings show that the non-Newtonian single-phase model generally provides better agreement with experimental measurements, particularly for emulsions with low dispersed phase fractions. Nevertheless, for emulsions with a high dispersed phase fraction (≈ 50%), the difference between the two approaches is insignificant. Thus, due to the lack of a universal multiphase model for emulsion simulation, the non-Newtonian single-phase model can serve as a viable alternative, overcoming the limitations of two-phase approaches in simulating complex multiphase fluid systems.
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    A reduced-order method with PGD for the analysis of mis- aligned journal bearing
    (2021) Megdoud, Abdelhak; Manser, Belkacem; Belaidi, Idir; Bakir, Farid; Khelladi, Sofiane
    n recent years, machine component design has been a major con- cern for researchers. Emphasis has been placed especially on the analysis of bearing systems in order to avoid detrimental contact. The shaft misalignment is one of the most problems that affects directly the operating conditions of these components. In this context, the present study proposes a reduced-order method "Proper Generalized Decomposition" (PGD) using the separation tech- nique through the alternating direction strategy to solve the modified Reynolds equation, taking into account the presence of misalignment in the shafting sys- tem. The solution shows the representation of two types of misalignment ge- ometry, especially axial and twisting. A comparison of the results between the proposed approach and the classical method, through several benchmark ex- amples, made it possible to highlight that the new scheme is more efficient, converges quickly and provides accurate solutions, with a very low CPU time expenditure.
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    Numerical study of the performance loss of a centrifugal pump carrying emulsion
    (2021) Achour, Lila; Mathieu, Specklin; Belaidi, Idir; Kouidri, Smaine
    The 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).
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    Numerical analysis of steady-state performances of hydrodynamic misaligned journal bearings considering surface texturing effects
    (2018) Manser, Belkacem; Belaidi, Idir; Khelladi, Sofiane; Hamrani, Abderrachid
    Misalignment affects nearly all the bearing performance characteristics including the minimum film thickness, pressure field, friction torque, leakage flow rate, and moments. This study presents investigations related to the combined influences of shaft misalignment and texture location on the hydrodynamic journal bearing performances. A numerical study is used in the analysis of spherical texture shape effects on misaligned bearing characteristics. The Reynolds equation of thin viscous films is solved using finite difference technique by taking into account Reynolds boundary conditions. The numerical results show that the performances of misaligned journal bearings can be improved through an appropriate arrangement of the textured location on the contact surface
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    Thermal analysis of steady-state performances of hydrodynamic misaligned journal bearings considering surface texturing effects
    (2018) Manser, Belkacem; Belaidi, Idir; Khelladi, Sofiane; Hamrani, Abderrachid
    Bearing misalignment can affects nearly all operating performances: minimum film thickness, pressure distribution, thermal field, friction torque, leakage flow rate, and cavitation. In this study, we present a computational investigation related to the combined influence of surface texturing and journal misalignment on the performances of hydrodynamic journal bearing. To this end, a numerical analysis is performed to analyze the effect of a spherical texture shape on misaligned bearing characteristics. The model employed herein is solved using a finite differences scheme with mass conservation algorithm (JFO boundary conditions) and oil mixing temperature concept. Preliminary results are consistent with the reference ones, and show that the performances of a misaligned journal bearing can be improved with an appropriate surface texturing topography
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    Damage Detection in Truss Structures Using Transmissibility Combined with Optimization Techniques
    (Springer link, 2020) Zenzen, Roumaissa; Khatir, Samir; Belaidi, Idir; Magd, Abdel Wahab
    The paper presents an effective approach based on Modal Assurance Criterion (MAC) formulation, transmissibility function and Particle Swarm Optimization (PSO) for damage assessment in truss structures. The Finite Element Method (FEM) is used to build the structures using Matlab. The main purpose of this study is to apply the transmissibility technique as an objective function based on MAC formulation to predict the damage location and severity. The objective function used in the proposed approach is based on transmissibly using MAC formulation (TMAC). The results show that the present methodology can reliably identify damage scenarios with higher accuracy even in case of complex structures
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    Correction de trajectoires d’outils en usinage deux axes
    (2003) Mir, Abdellah; Belaidi, Idir
    Dans cet article, nous présentons un système de compensation de trajectoires d’outils permettant de corriger les trajectoires d’outils en fraisage 2 axes et de respecter ainsi une tolérance prescrite. Ce système est basé sur une stratégie de calcul de la déflexion d’outil s’appuyant sur un modèle d’effort de coupe statique et trois méthodes de correction différentes. L’étude expérimentale effectuée nous a permis d’étudier les performances de ces méthodes de correction en fonction des paramètres d’usinage : diamètre et longueur d’outil et avance par dent
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    Les méthodes d’approches en conception mécanique routinière
    (2003) Semmoud, Fath-Eddine; Belaidi, Abderrahmane; Belaidi, Idir
    Un objet (de type machine outil) passe nécessairement par la phase de conception qui est la première phase du cycle de vie d’un produit. Les très grandes avancées qu’a connu l’industrie et les développements de différents produits après la seconde guerre mondiale ont commencé après les deux guerres mondiales. La conception mécanique n’est pas un simple processus, elle est plutôt un ensemble de processus. Elle est l’incarnation de la connaissance des fonctions et des interactions des composants impliqués dans le mécanisme. Même si beaucoup de développements sont en cours actuellement, le processus reste à développer, analyser et, avec l’avènement de l’informatique, à formaliser mathématiquement et à implémenter. L’intégration de la conception mécanique, dans l’industrie algérienne comme pour les pays en voie de développement, sera importante dans l’optique d’assurer la maintenance de l'outil de production (dans un premier temps) et de développer des bases de connaissances qui seront la source de création de nouveaux produits pour un second. Nous proposons dans cet article la présentation de quelques méthodes d'approche utilisées et développées que nous avons pressenties nous permettre l’implémentation de conception routinière
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    Intégration du tolérancement dans les système de CFAO : méthode de synthèse statistique des tolérances par estimation des graduents
    (2004) Boucherit, B.; Belaidi, Idir; Belaidi, Abderrahmane; Chalali, M.O.
    L’intégration de la cotation automatique dans les systèmes de CFAO est plus que jamais d’actualité. Les systèmes actuellement disponibles restent incomplets et demeurent tous perfectibles ; les méthodes d’analyse et de synthèse font toujours l’objet de recherche et de développement continus. La synthèse statistique des tolérances par estimation des graduents jouit d’une simplicité de mise en oeuvre (utilisation des distributions discrètes au lieu des distributions continues), d’un temps de calcul réduit des dérivées par rapport à la méthodes des différences finis, d’une précision appréciable pour le calcul des tolérances intervenant dans le coût et la performance du produit (perte de qualité importante, coût de fabrication important)
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    Application et adaptation de la triangulation de Delaunay pour la reconstruction de surfaces = Surface reconstruction using and adapting Delaunay triangulation
    (2004) Challali, Mohand Oulhadj; Belaidi, Idir; Mohammedi, K.; Belaidi, Abderrahmane; Ishiomin, Guy
    La reconstruction intéresse plusieurs domaines d'application et de recherche. Parmi ceux-ci nous trouvons: la génération d'un modèle CAO, la simulation, l'inspection et le contrôle, l'usinage, technologie des prothèses, assistance au diagnostic médical, vision robotique et artificielle, reconnaissance de terrains,…etc. Parmi les techniques de reconstruction d’une surface, nous trouvons celle qui procède par polyèdrisation du nuage de points [Ver 98], [Var 97]. Dans ce papier, nous proposons une telle technique basée sur l’adaptation et l’utilisation de la triangulation de Delaunay en dimension 2D1/2