Arabian Journal for Science and Engineering最新文献

This article outlines techniques for optimizing input parameters for the welding process, such as welding current, speed, and gas flow rate in relation to weld bead geometry and Dilution, using Response Surface Methodology (RSM). In the wire arc additive manufacturing (WAAM) process, single-weld bead stability and quality play a prominent role in the final manufactured part's quality and shape. A single-bead geometry model was initially established using RSM, and experiments were carried out using a central composite design of experiments for depositing Inconel 718 in WAAM. The design factors and responses were analyzed using multiple regression equations, and the validity of the resulting regression equations was evaluated using ANOVA. The researchers fabricated a multi-layer structure with optimal parameters, including a welding current of 210 A, 6.91 mm/s speed, and a gas flow rate of 25 l/min. Optical microscopy characterized the microstructures, revealing small dendritic grains in the top layer, equiaxed in the middle and side regions, and columnar in the lower region. The current study benefits industrial applications for developing the Inconel 718 superalloy WAAM structure.

This paper presents a unique five-level inverter consisting of one DC voltage source and one capacitor. Here the capacitor acts like another source and is fed to the inverter along with the DC voltage source. The DC voltage source is also used to charge the capacitor with the help of an additional switch used inside the converter circuit. An inductor is used in the charging path to reduce the peak of the charging current. The in-phase disposition sinusoidal pulse-width modulation technique is used to generate the gate pulse for the devices of the presented converter. The proposed topology operates in two modes. One is energy stored mode and another is energy release mode. By using both modes of operation, the additional switch is triggered to charge the capacitor. The capacitor’s charging and discharging mode and inverter power loss have been described thoroughly in this paper. The proposed five-level inverter topology has been developed and verified inside the laboratory. The controller of the converter has been implemented in the FPGA platform. The experimental results are obtained to evaluate the efficacy of the proposed inverter.

The primary focus of the current study is to examine the effect of magnetohydrodynamics on the peristaltic motion of Eyring–Powell fluid. The Navier–Stokes equations, renowned for their intricate nature, form the foundation of the mathematical model utilised in this investigation. However, the model has been simplified through specific assumptions to facilitate analysis. The model assumes explicitly a long wavelength and a low Reynolds number. This study also investigates the effect of wall characteristics on peristalsis in the presence of a magnetic field. Additionally, variable liquid properties such as varying viscosity and thermal conductivity are also considered in the study. The governed nonlinear equations are solved with multiple slip conditions to obtain the velocity, temperature, concentration and streamline profiles. Different waveforms on velocity profiles are also studied. A parametric evaluation makes the analysis more accessible, and the results are graphically depicted using MATLAB R2023a software. The findings of this study shed light on the substantial impact of the magnetic parameter and varying viscosity on fluid properties.

This study explores a novel approach to quenching and partitioning (Q&P) heat treatment applied to AISI 9260 spring steel, comprising Fe-0.65C-1.58Mn-1.05Si-0.41Cr (wt.%). Our research focuses on balancing strength and ductility through optimized Q&P pathways, leading to a diverse microstructure that includes martensite, bainite, carbide, and retained austenite. Advanced X-ray diffraction and scanning electron microscopy techniques were employed to analyze the complexities of this microstructure. A key aspect of this study is the precise control of partitioning temperature and time, crucial for modulating lattice distortion and dislocation density within martensitic and bainitic structures. Optimal partitioning temperature promotes carbon distribution into austenite, tempering lattice distortions, and dislocation densities. Concurrently, carbide precipitation and segregation contribute to the refinement of the bainite phase. The sample quenched at 125 °C and partitioned at 350 °C (Q&P-125/350) demonstrates notable mechanical properties: a yield strength of 950 ± 15 MPa, an ultimate tensile strength of 1710 ± 15 MPa, and an elongation of approximately 9.7%. These results are partly attributed to the effect of silicon in preventing cementite coarsening and the effective distribution of carbide. Our findings highlight the potential of Q&P heat treatment in developing tailored microstructures with enhanced mechanical properties in steel, without relying on costly alloying elements. This approach presents new avenues for the design and application of high-performance materials.

The effect of the seabed on the hydrodynamics of three-dimensional autonomous underwater vehicles (AUVs) varies according to the physical conditions of the place where AUVs interact with the environmental conditions. This study examines the hydrodynamics of an AUV resembling a torpedo model while taking the influence of the seabed surface as a function of the dimensionless distances (G/D) between the torpedo and the seabed. Reynolds numbers, varying from 1 × 10⁴ to 8 × 10⁴, were considered. These Reynolds numbers were associated with various seabed distances falling within 0.25 ≤ G/D ≤ 1.5. To perform the simulations, governing equations were utilized and incorporated with the k–ω SST turbulence model. It has been observed that when AUVs or torpedo models operate in close proximity to the seabed surface, several key hydrodynamic parameters and flow characteristics are affected. These include the pressure coefficient (C_p), drag coefficient (C_D), overall flow structures, maneuverability, and performance of the torpedo model. As the AUV or torpedo model approaches the seabed surface, the symmetrical flow pattern deteriorates. This deterioration is associated with changes in vortical flow structures under the influence of seabed surfaces. Additionally, the intensity of the shear stress (τ) near the seabed surface gradually increases as the AUV or torpedo model gets closer to it. In summary, the proximity of AUVs or torpedo models to the seabed surface causes disruptions in the flow patterns, increased shear stress, and alterations in key hydrodynamic parameters, ultimately affecting the system's performance and behavior.

This paper presents the effectiveness of a hybrid YUKI-RANDOM-FOREST, Particle Swarm Optimization-YUKI (PSO-YUKI), and balancing composite motion optimization algorithm (BCMO) based on artificial neural networks (ANN) for the best prediction of patch design considering the maximum principal stress. The study compares the maximum principal stress in a damaged pipe under different composite patch designs. Robust models have been developed and utilized in various applications. The research investigates the influence of cracks on the mechanical characteristics of API X70 steel in a test pipe under critical pressure. The numerical model employs the extended finite element method (XFEM) to simulate notches. Extending the optimization technique, the study examines the effect of crack presence in a pipeline section under internal pressure without and with composite repairs on the maximum principal stress. The sensitivity of stress is analyzed with respect to the design parameters of the composite patch. Finally, YUKI-RANDOM-FOREST, NN-PSO-YUKI, and NN-BCMO, with different parameters and hidden layer sizes are employed to predict the maximum principal stress under different composite patch designs, and yielding minimal error. Once the database was built, our model was prepared to predict various situations at the composite patch level. Compared to other methods, the obtained results with hybrid YUKI-RANDOM-FOREST are effective. The investigation technique is relevant to real-world engineering applications, structural safety control, and design processes.

This paper proposes a combination of a nonlinear feedback linearization control (FLC) and a second-order sliding mode (SOSM) controller to enhance the effectiveness and performance of variable speed control in an open-ended winding induction motor (OEWIM). The literature indicates that the traditional FLC with a PI controller is susceptible to disruptions from its internals as well as outside interference. The conventional sliding-mode controller can offer robust control. However, it suffers from the chattering phenomenon. The SOSMC, based on a super-twisting algorithm (STA), was designed and implemented to overcome all of these drawbacks. It is extremely difficult to obtain the optimum parameters for each FLC and SOSM controller that give good results using traditional methods due to the relatively large number of parameters. Moreover, a novel approach based on the linearly decreasing method for both inertia weight and learning constant of the particle swarm optimization (PSO) algorithm was presented to improve the variable speed control of the OEWIM. To maintain a constant switching frequency, decrease harmonic distortion, and reduce common-mode voltage (CMV), a space vector modulation technique of a seven-level inverter is suggested and implemented by supplying each end of an open-ended stator winding induction motor with three-level inverters. The advantages of the suggested control system have been confirmed using simulated results of various tests of the complete system.

The present study evaluated the effectiveness of a blend of dimethyl ketone (DMK) and methyl esters extracted from vegetable sesame oil (VSO) as a flow improver. The rheological impact of the additive on crude oil was assessed at various ratios (500, 1000, and 1500 ppm), shear rates (1.86–233 s⁻¹), and temperatures (5–30 °C). This study employed three models, Bingham plastic, power law, and Herschel–Bulkley, to evaluate the experimental data and determine the consistency factor and flow index of the oil samples considered. The average viscosity reduction (VR), thermal effects, activation energy, and yield stress of the additive were also assessed. The findings revealed that the blend enhanced crude oil flowability at low temperatures. Furthermore, at 1500 ppm and 1.86 and 46.5 s⁻¹ shear rates, the viscosity was diminished to 90.5% and 89.8%, respectively. The viscosity reduction was more significant at and over 100 s⁻¹ shear rates at temperatures up to 30 °C. Increasing dosage and temperature decreased yield stress and activation energy, (E_{{text{a}}}), which reached 30.479 kJ mol⁻¹. The experimental data obtained in this study fitted the Herschel–Bulkley and power law models, approaching Newtonian behaviour at 1000 ppm. Moreover, the consistency index (k) of the crude oil incorporated with the additive diminished to 0.10386 and 0.029712, respectively. At 1500 ppm, the flow behaviour index (n) of the crude oil improved to 0.9665 and 0.9894 at 5 °C and 30 °C, respectively. The results demonstrated that the additive derived from natural seeds was an eco-friendly alternative flow improver.

The increased demand for lightweight structural materials in the transport sector has compelled researchers to develop materials with high strength and reduced structural weight, aiming to enhance vehicle performance, minimize fuel and oil consumption and reduce CO₂ emissions. However, their structural weight and strength still need to be improved. Herein, an attempt has been made to fabricate aluminum-based composites reinforced with hexagonal boron nitride (h-BN: 1,3,5,7 wt% ) and multi-walled carbon nanotubes (MWCNTs: 0.25, 0.5, 0.75, 1 wt%) through powder processing method. The results revealed that the 3BN/Al composite disclosed better densification (96.8%) and hardness (49 ± 1.5) among all BN/Al composites. Furthermore, the addition of 0.5 wt% CNTs to BN/Al composite significantly improved the densification (97.7%), Vickers hardness (106%) and tensile strength (189%) over pure Al. This improvement was attributed to homogeneously distributed h-BN and CNTs in the Al matrix and the formation of hard aluminum carbide (Al₄C₃) phase. The results demonstrate that BN/CNTs/Al composite exhibits superior mechanical strength, making them promising structural and functional materials for aerospace and automobile industries.

The present work was designed to study the influence of zinc doping on the structural, biological and dye degradation properties of biogenic magnesium oxide nanoparticles (MgOSA NPs). Pure MgOSA and zinc doped MgOSA NPs were synthesized using S. androgynus leaf extract as fuel. The obtained NPs were scrutinized for their morphological and surface properties through various techniques. The results of FTIR, FESEM, HRTEM and EDS studies accompanied by elemental mapping analysis evidenced the formation of targeted NPs. Whereas the PXRD analysis substantiated the formation of pure and zinc doped NPs with crystallite size 24.29 and 17.47 nm respectively. Additionally, the refinement of obtained PXRD data through Rietveld refinement corroborated the changes in cell parameters after zinc doping. The BET analysis performed divulged the mesoporous nature of NPs having surface areas 30.245 and 10.058 m²g⁻¹ respectively. The biocompatibility of NPs was confirmed via in-vitro anti-inflammatory study which exhibited % HRBCS up to 85.38 ± 0.003 and 87.42 ± 0.005 for MgOSA and ZnMgOSA NPs. The glucose-lowering potentiality via α-amylase inhibition assay manifested the appreciable in-vitro antidiabetic property of synthesized NPs (76.79 ± 0.001 and 77.24 ± 0.0005%). Also, the NPs exhibited antibacterial activity against Pseudomonas syringae, Escherichia coli, Pseudomonas aeroginosa, Staphylococcus aureus and Bacillus subtulis. Furthermore, the photocatalytic experiments performed on Methylene Blue dye have revealed an excellent degradation efficiency of MgOSA and ZnMgOSA NPs with high stability and reusability.