Yanbu Journal of Engineering and Science (YJES)
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202 research outputs found
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EFFECT OF FRICTION STIR WELDING ON MECHANICAL PROPERTIES OF DISSIMILAR WELD JOINTS
No full textFriction stir welding (FSW) is a novel solid state welding process for joining metallic alloys and has emerged as an alternative technology used in high strength alloys that are difficult to join with conventional techniques. The applications of FSW process are found in several industries such as aerospace, rail, automotive and marine industries for joining aluminum, magnesium and copper alloys. The FSW process parameters such as rotational speed, welding speed, axial force and attack angle play vital roles in the analysis of weld quality. The aim of this research study is to investigate the effects of different welding speeds and tool pin profiles on the weld quality of AA6082-Al 5083. This material has gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to-weight ratio. Circular and squared pin are used as tool pin profiles in this research. The appearance of the weld is well and no obvious defect is found using these tools. Consequently, the obtained results explain the variation of stress as a function of strain and the effect of different welding speed and pin profiles on yield strength ultimate tensile strength and elongation
ON PRESSURE DROP THROUGH BRANCHED DUCTS
No full textAn experimental loop was designed and constructed in order to simulate air duct systems usually adopted in industrial processes. In this work, the loop consisted of two main branches; each branch could be fixed at desired angle of inclination ranging from 15° to 90° from the axis of the main duct. The losses of energy due to pressure drop through the duct were measured at different points through the loop. Experiments were performed at different flow rates with various air exits at Reynolds number between 4.6×10¹ and 10.2×10. The objectives of the present work are to predict the pressure losses through air in the variable volume control system as well as to determine the optimum angle of inclination to cause minimum pressure drop. It has been found that the percentage of the air exit opening and the degree of inclination of branched duct have significant influence on the energy losses due to the pressure drop. Results from the present study showed that with an angle of 90° and a full exit opening as well as with an angle of 15° and 75% of the exit opening, the pressure drop reached its minimum value. This can be attributed to the existence of the secondary flow within the elbow. It was also observed that more narrowing of air exit resulted in increased generation of back pressure inside the duct at different sections. This significant observation makes it possible to rely upon the design of the present loop when the air variable volume control system is utilized in industry
Electrochemical Deposition of Highly Catalytically Active Palladium Nanoparticles - Application to Methanol Fuel Cell Anodes and its Kinetic Studies
No full textFuel cell technology is a green and promising energy source for the future generation. Amongst all fuel cells, methanol oxidation with very low overpotential at modified electrodes is important for understanding and developing methanol fuel cell anodes. Platinum (Pt) is a well-known catalyst for the methanol oxidation reaction. However, Pt is expensive and also methanol oxidation intermediates adsorbs very strongly onto its surface. In the present study, a less expensive and highly active electrocatalyst was developed using palladium (Pd) by simple electrochemical technique. The scanning electron microscope (SEM) displays that small sized nanoparticles are in the range of 4-8 nm. The prepared material shows excellent electrocatalytic activity with quite low overpotential at room temperature. In addition, to understand the kinetics, energy of activation was determined by studying the methanol oxidation reaction at different temperature. The onset potential decrease with increasing temperature implies that the kinetics of the process improves at elevated temperature. The lowest activation energy was found to be 20 kJ/mol which is almost comparable with many Pd based materials
A NOVEL VARIABLE HYSTERESIS BAND CURRENT CONTROLLED VSI FED INDUCTION MOTOR DRIVES
No full textThe most problem associated with the conventional two-level three phase hysteresis controller is variation of switching frequency over the entire operating speed range of an induction motor (IM) drive. This paper presents a new variable band hysteresis current controller (NVB-HCC) for controlling the switching frequency variation in the two-level PWM inverter fed IM drives for various operating speeds. A novel concept of online variation of the band based on both the instantaneous load current and current change for each sampling period is presented to determine the hysteresis band. To verify the feasibility of the proposed scheme, computer Simulations and experiment results are provided. These results demonstrate that the proposed method can obtain constant switching frequency and improve the performance of the IM drive system
FAULT TOLERANT CONTROL OF INDUCTION MOTOR FED BY THREE PHASE INVERTER
No full textIn this paper a new switching technique for Direct Torque Control (DTC) fault tolerant induction motor drive is presented, if one inverter leg is completely lost due to such abnormal condition, this system modifies the switching table of DTC system using the available stator voltage vectors in two phase mode with Four Switch Three Phase Inverter (FSTPI) topology to track the stator flux reference and directly control the torque and maintain the performance of induction motor as in the Six Switch Three Phase Inverter (SSTPI) mode. An experimental setup has been built in Laboratory using the interface circuit Advenchtech PCI 1711 to test the performance of the proposed method and the experimental results give a good agreement with the simulation results
Influence of Electrolyte Concentration on Metal Removal Rate and Surface Finish Quality in Electrochemical Machining Masking
No full textElectrochemical machining (ECM) is a specialized and precise manufacturing technique involving selective metal removal to achieve the desired shape or form. This article’s primary focus is examining the technical facets associated with the procedure. The elements mentioned encompass the system’s design and optimization, the electrolyte solution’s careful selection, and the precise control of the etching parameters. When considering the overall framework, it is essential to consider important factors such as the concentration of electrolytes, the operational voltage, and the value of the current flowing through the system. The main objective of this study is to evaluate the influence of different concentrations of sodium chloride electrolyte on the metal removal rate (MRR). This will be achieved by utilizing a direct current power supply. The present investigation used aluminum, steel, and stainless steel materials as the substrate for experimentation. These materials were selected to have identical dimensions for the anode and cathode. The main objective of this study is to evaluate the influence of varying concentrations (0.5, 1, 1.5, and 2 mole/liter) of sodium chloride electrolyte on the material removal rate and surface roughness. The findings have been disclosed, revealing the utmost removal rate for aluminum, steel, and stainless-steel materials across all levels of electrolyte concentration. The experimental information is currently presented, related to the rates of metal removal at various electrolyte concentrations of 2 moles per liter. The rates of mass loss observed in aluminum are comparatively higher when compared to those surveyed in steel and stainless steel. The roughness of a machined surface is inversely proportional to the concentration of the electrolyte
OPTIMIZATION OF DIESEL ENGINE PERFORMANCE AND EMISSION CHARACTERISTICS EMPLOYING HYBRID TAGUCHI-GTMA-UTILITY TECHNIQUE
No full textWith the advent of employing bio-fuels along with the diesel in compression ignition engines the study of performance and emission characteristics have occupied the prominence, owing to diversified multi responses. As the limited information is available about the application of Taguchi based GTMA process to maximize the overall performance and emission characteristics of diesel engine, in the present work the investigation was carried out to maximize the overall utility by employing the Taguchi based GTMA process. By following the user preference rating, weights for the response characteristics namely brake thermal efficiency, brake specific fuel consumption, carbon monoxide and oxides of nitrogen were calculated using graph theory and matrix approach (GTMA). The parameter hydrogen induction played a major role to an extent of 78.62% while Injection opening pressure playing a minor role with a contribution of 7.06%. The optimal parameters condition was at mid-level of the governing parameters namely IOP, CR and volume of hydrogen inducted. The predicted results were within 95% of confidence interval of the optimal values. Therefore, the hydrogen inductance into the cylinder not only improving the performance but also minimizing the emission characteristics
Potentializing Green-IoT, AI and 6G Technologies in Computational Thinking
No full textComputational thinking is a problem-solving approach that involves breaking down complex problems into smaller, more manageable parts and identifying patterns and relationships between different components whereas Green-IoT and Artificial Intellige- nce (AI) in 6G environment are important approaches for potentializing an effective Co- mputational Thinking solution. Al approaches involve developing algorithms that can le- arn from data, make predictions and decisions, and perform complex tasks without explic it programming. When it comes to Green-IoT, both computational thinking and Artificial Intelligence can be used to analyze and interpret the massive amounts of data generated by connected devices using 6G communication networks. This can lead to more intelligen t and efficient use of resources, as well as improved automation of various processes. The combination of Green-IoT, AI and 6G Technologies in computational thinking has the po- tential to transform various industries including the educational one and improve the quality of life for individuals is expected to lead to new applications and services that are more intelligent, efficient, and personalized. This research presents a review on computa -tional thinking, particularly, we first give an overview of essential parameters through Green-IoT enabled sensor technologies under 5G, 6G environment and Artificial Intellig- ence. We then present an overview of requirements of basic architecture for loT and Al based computational thinking system considering key attributes to potentialize social applications and discussing their strengths and weaknesses in the context of framework for community services. Finally, we present various security threats to an AI-based archi- tecture to design robust and resilient computational thinking services system needed in the context of social networking
A MODERATE WEIGHT EAP AUTHENTICATION METHOD (EAP-MEAP) FOR WIRELESS LOCAL AREA NETWORK
No full textIEEE 802.11standard for Wireless Local Area Networks (WLANs) is facing more and more problems linked to security threats, which expose legitimate users to increased risk. Therefore, the security is always a major concern for WLAN development and one of the major challenges in WLAN security issue is authentication. Extensible Authentication Protocol (EAP) has been widely used for that important aspect. EAP is a framework of authentication process that uses several methods to perform that process. In this paper, we will analyze and show up the flows of the existing EAP methods. Then, we will propose a new EAP method Extensible Authentication Protocol -Moderate Weight Extensible Authentication Protocol EAP-MEAP . This method combines between the simplicity of deployment and management of password methods and the robustness of certificated ones. EAP-MEAP can be used widely in IEEE802.11 for WLANs (Wi- Fi and its application domains) as solution to the presented flaws. We present a security assessment to our proposed protocol. Finally, we have checked and verified the EAP- MEAP security properties using the specialized model checker AVISPA, which provides formal proofs of the security protocols
INVESTIGATION OF FLUID STRUCTURE INTERACTION (FSI) EFFECT ON A FRP (FIBER REINFORCED POLYMER) POLE USING ANSYS
No full textThis paper presents a simulation study on a fiber-reinforced polymer (FRP) light pole that is being used in Yanbu Industrial City, Saudi Arabia. The light poles in this area are subjected to cyclic wind load blowing from the Red Sea. It is of great interest to re-investigate the strength and integrity of the structure for future improvement. A three-dimensional numerical simulation has been performed to analyze the effect of wind velocity over the FRP pole. The pole is conical in shape, having a circular hollow cross-section in both the ends and tapered uniformly. The pole considered for simulation is having a height of 6 meters and have conicity of 18 mm/m. The FRP pole is a combination of unsaturated polyester, vinyl ester, epoxy, phenolic, polyurethane, and glass fibers, which are reinforced by the centrifugal process. The computational fluid dynamics (CFD) simulation results are validated with the mathematical calculation. The adopted method is fluid-structure interaction (FSI) with SST k-o (shear stress transport) turbulence model, which is used to simulate the wind velocity over the FRP pole using ANSYS Fluent. The velocity of air considered for simulation ranges from 10 to 50 m/sec. The study provided a good correlation between mathematical calculation and the CFD simulation for each air velocity. The study revealed maximum deflection and equivalent stress occurred at the top and bottom end, which are 217 mm and 85 MPa respectively. The exact region of crack is also predicted for different wind velocity. This method can also be adopted for any FRP poles available