Browsing by Author "Khelladi, Sofiane"

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Coupling of inverse method and cuckoo search algorithm for multiobjective optimization design of an axial flow pump
(Sage journals, 2019) Abdessamad, Mohamed; Ait Chikh, Mohamed Abdessamad; Belaidi, Idir; Khelladi, Sofiane
his work describes the application of a multiobjective cuckoo search method for turbomachinery design optimization of an axial pump. Maximization of the total efficiency and minimization of the required net positive suction head of the pump are the two objective functions considered for the optimization problem. The optimization process is carried out on a range of imposed volumetric flow rates, with taking into account at each discretized radius between the hub and tip of the rotor: the profile camber, rotor wall thickness, angular deviation, and the solidity, regarded as geometrical constraints and nominal flow rate as mechanical constraint. Two strategies are proposed in order to solve the problem. In the first one, three forms of mono-objective model with two variables, total efficiency and net positive suction head, are considered. In the second one, a multiobjective model with nondominated sorting scheme is adopted. A comparative evaluation of results obtained from the proposed approach with those of a reference machine and genetic algorithm allowed us to validate the present work
Coupling of inverse method and cuckoo search algorithm for multiobjective optimization design of an axial flow pump
(SAGE Publications, 2019) Chikh, Mohamed Abdessamed Ait; Belaidi, Idir; Khelladi, Sofiane; Hamrani, Abderrachid; Bakir, Farid
This work describes the application of a multiobjective cuckoo search method for turbomachinery design optimization of an axial pump. Maximization of the total efficiency and minimization of the required net positive suction head of the pump are the two objective functions considered for the optimization problem. The optimization process is carried out on a range of imposed volumetric flow rates, with taking into account at each discretized radius between the hub and tip of the rotor: the profile camber, rotor wall thickness, angular deviation, and the solidity, regarded as geometrical constraints and nominal flow rate as mechanical constraint. Two strategies are proposed in order to solve the problem. In the first one, three forms of mono-objective model with two variables, total efficiency and net positive suction head, are considered. In the second one, a multiobjective model with nondominated sorting scheme is adopted. A comparative evaluation of results obtained from the proposed approach with those of a reference machine and genetic algorithm allowed us to validate the present work
Efficiency of bio- and socio-inspired optimization algorithms for axial turbomachinery design
(Elsevier, 2017) Ait Chikh, Mohamed Abdessamad; Belaidi, Idir; Khelladi, Sofiane; Paris, José; Deligant, Michael; Bakir, Farid
An efficient reduced-order method with PGD for solving journal bearing hydrodynamic lubrication problems
(Elsevier, 2016) Cherabi, Bilal; Hamrani, Abderrachid; Belaidi, Idir; Khelladi, Sofiane; Bakir, Farid
Experimental study on the effects of big particles physical characteristics on the hydraulic transport inside a horizontal pipe
(Elsevier, 2016) Zouaoui, Salah; Djebouri, Hassane; Mohammedi, Kamal; Khelladi, Sofiane
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
Performance of hydrodynamic journal bearing under the combined influence of textured surface and journal misalignment : a numerical survey
(Elsevier, 2019) Manser, Belkacem; Belaidi, Idir; Hamrani, Abderrachid; Khelladi, Sofiane; Bakir, Farid
A reduced-order method with PGD for the analysis of dynamically loaded journal bearing
(2022) Megdoud, Abdelhak; Manser, Belkacem; Belaidi, Idir; Bakir, Farid; Khelladi, Sofiane
Machine component design has become a prominent topic for researchers in recent years. The analysis of bearing systems has received considerable attention in order to avoid detrimental contact. Among the most important studies in this area are the transient problems of journal bearings, which are usually performed by coupling the Reynolds equation with the motion equations. Many techniques have been presented in the literature and are still being explored to ensure the accurate findings and efficient solution prediction of unsteady state Reynolds equation. In this paper, the Proper Generalized Decomposition (PGD) approach is expanded for the analysis of the lubricant behavior of dynamically loaded journal bearing considering Swift-Stieber boundary conditions. The PGD model is applied in this problem, seeking the approximate solution in its separated form of the partial differential Reynolds equation at each time step during the load applied cycle employing the alternating direction strategy. Compared to the classical resolution, the PGD solution has a considerably low computational cost. To verify the accuracy and efficiency of this approach, three cases have been considered, infinitely short, infinitely long and finite journal bearings under the dynamic load. The results of the suggested methodology when compared to the full discretized model (FDM) show that, the new scheme is more efficient, converges quickly, and gives the accurate solutions with a very low CPU time consumption.
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.
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
Topological optimization of dimple distribution for enhanced performance in hydrodynamic porous self-lubricating journal bearings with sealed ends
(Sage, 2025) Ifrah, Walid; Manser, Belkacem; Chellil, Ahmed; Ragueb, Haroun; Mechakra, Hamza; Khelladi, Sofiane; Belaidi, Idir
This study numerically investigates the impact of optimal textures location on the performance of hydrodynamic porous self-lubricating journal bearings with sealed ends, subjected to a stationary load. The analysis employs a modified Reynolds equation coupled with Darcy’s law to model fluid flow in both the lubricating film and the porous matrix, considering the hydrodynamic self-lubrication problem. The governing nonlinear PDE systems were solved numerically using the finite difference method, combined with Reynolds boundary conditions and continuity conditions for velocity and pressure at the film-bush interface. A Binary Genetic Algorithm (BGA) is employed to optimize the topological distribution of square dimples in the textured porous layer to enhance bearing performance. The study investigates the influence of key parameters, including applied load, rotational speed, permeability, and texture depth, on bearing characteristics such as minimum film thickness and friction coefficient. Results show good agreement with benchmark data and indicate a positive enhancement in porous bearing performance. In addition, findings demonstrate that increasing the permeability of the porous structure reduces bearing performance (up to 25% in minimum film thickness and 8% in friction coefficient). However, the application of the optimization technique identified an optimal arrangement of textures that compensates for these performance losses, even under severe working conditions. Texturing the outlet region of the contact (beyond 180°) at the cavitation zone causes a micro-step bearing mechanism, generating localized pressure recovery within the textured area, significantly enhancing the minimum film thickness (up to 12%), reducing friction (up to 23%), and minimizing cavitation (up to 24%).
Towards an accurate aerodynamic performance analysis methodology of Cross-Flow fans
(MDPI, 2022) Himeur, Rania Majda; Khelladi, Sofiane; Ait Chikh, Mohamed Abdessamad; Vanaei, Hamid Reza; Belaidi, Idir; Bakir, Farid
Cross-flow fans (CFFs) have become increasingly popular in recent years. This is due to their use in several domains such as air conditioning and aircraft propulsion. They also show their utility in the ventilation system of hybrid electric cars. Their high efficiency and performance significantly rely on the design parameters. Up to now, there is no general approach that predicts the CFFs’ performance. This work describes a new methodology that helps deduce the performance of CFFs in turbomachinery, using both analytical modeling and experimental data. Two different loss models are detailed and compared to determine the performance–pressure curves of this type of fan. The efficiency evaluation is achieved by realizing a multidisciplinary study, computational fluid dynamics (CFD) simulations, and an optimization algorithm combined to explore the internal flow field and obtain additional information about the eccentric vortex, to finally obtain the ultimate formulation of the Eck/Laing CFF efficiency, which is validated by the experimental results with good agreement. This approach can be an efficient tool to speed up the cross-flow fans’ design cycle and to predict their global performance