Communications Internationales
Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/11
Browse
4 results
Search Results
Item 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, IdirComputational 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.Item Numerical analysis of steady-state performances of hydrodynamic misaligned journal bearings considering surface texturing effects(2018) Manser, Belkacem; Belaidi, Idir; Khelladi, Sofiane; Hamrani, AbderrachidMisalignment 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 surfaceItem Thermal analysis of steady-state performances of hydrodynamic misaligned journal bearings considering surface texturing effects(2018) Manser, Belkacem; Belaidi, Idir; Khelladi, Sofiane; Hamrani, AbderrachidBearing 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 topographyItem Damage Detection in Truss Structures Using Transmissibility Combined with Optimization Techniques(Springer link, 2020) Zenzen, Roumaissa; Khatir, Samir; Belaidi, Idir; Magd, Abdel WahabThe 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
