فهرست مطالب

Engineering - Volume:34 Issue: 9, Sep 2021

International Journal of Engineering
Volume:34 Issue: 9, Sep 2021

  • تاریخ انتشار: 1400/06/03
  • تعداد عناوین: 16
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  • H. Parivar, S.M. Seyyedbarzegar *, A. Darabi Pages 2045-2052
    This paper are concentrated on low-speed surface-mounted permanent magnet synchronous generator (LS-SMPMSG) electromagnetic design using finite-element (FEM)-based method. Introduced LS-SMPMSG as an important generator in the industry is utilized in marine energy conversion (MEC) and tidal energy conversion (TEC) systems. The main feature of the designed LS-SMPMSG exhibited is its ability to generate electrical power in MEC and TEC systems at a low speed of approximatively 100 rpm. In this paper, a new slot structure for LS-SMPMSG has been proposed to enhance the LS-SMPMSG performance. The FEM analysis and comparing results shows that the new slot structure reduced the torque ripple and the cogging torque equal to 19.54% and 87.5%. respectively. Also, it influenced the LS-SMPMSG Joule losses by reducing it close to 16.1%. Another advantage of the new slot structure of LS-SMPMSG is its easy construction and assembly. The FEM analysis as a powerful method validates the advantages of the proposed structure.
    Keywords: Marine Energy Conversion System, Tidal Energy Conversion System, XLPE, Finite element method, Torque Ripple, Joule loss
  • I. Sabree, M. Aswad *, H. Abd Ali Pages 2053-2059
    Bioactive glass-ceramic is used as a replacement material for bone tissue due to its compatibility, bioactivity, and the ability to form a crystallized hydroxyapatite layer, which is similar in composition and structure to the inorganic component of the bone mineral phase. In this paper, bioglass-ceramic was toughened using zirconia to improve its mechanical behaviour (i.e. crack opening dsplacement and fracture toughness). The fracture toughness of the bioactive glass cerami/zirconia composite was measured using three-point bending technique. Digital Image Correlation (DIC) technique was utilized for visualized the crack initiation and calculation the crack opening displacement (COD) at the tip and mouth of the crack and measuring of the crack propagation of the bioactive glass cerami/zirconia composite. The results indicated that the incorporation of the zirconia particles improved the measured fracture toughness of the BGC/ZrO2 composite. The toughness of composite bioceramics is enhanced due to crack branching and crack deflection due to the presence of zirconia particles.
    Keywords: Advanced Ceramic, Mechanical Behaviour of Materials, Fracture mechanics, and Corrosion
  • D. Bharti * Pages 2060-2069
    With some assumptions and limitations, various methods have been developed in literature mainly for loss allocation in transmission network and afterwards extended for radial distribution network and some methods are specifically developed for radial distribution network. But, these methods are not suitable for microgrids which are integrated with conventional grid at sub-transmission and distribution levels depending on their geographical location. This paper presents a loss allocation method based on power flow results and relative position of buses for interconnected microgrid which is very effective in case of frequent change of generations due to intermittent nature of renewable resources. The implementation of the proposed method is very simple in microgrid with both meshed as well as radial topology without any computational complexity and requires only power flow solution and network data. The results are illustrated for different generating conditions of renewable sources in microgrid to demonstrate the efficiency of proposed loss allocation method.
    Keywords: Loss allocation, microgrid, Variable generation, Power flow solution, Relative position
  • A. Ebadi, S. M. Hosseini *, A. A. Abdoos Pages 2070-2076

    The restricted earth fault (REF) protection is provided for electrical power transformer in order to sense internal earth faults, mainly because it is more sensitive than the main differential protection. However, The REF relay may maloperate when current transformer (CT) saturation happens following a severe external fault. In this paper, a new simple algorithm is proposed for REF protection scheme which is realized by considering four fundamental conditions. These conditions are defined based on the differential and neutral currents as well as sum of phase currents. When these conditions are simultaneously satisfied, the relay detects the internal ground fault. This algorithm is implemented and evaluated by MATLAB program based on obtained result data from simulation of a real power system using PSCAD/EMTDC software package. The well-known Jiles-Atherton (JA) model is used to simulate the transient behavior of CTs. The satisfactory results obtained from exhaustive investigation justify the high security of the proposed protection scheme.

    Keywords: Power Transformer Protection, Restricted Earth Fault, Jiles-Atherton Model, Current Transformer Saturation
  • M. Taheri, J. Arkat *, H. Farughi, M. Pirayesh Pages 2077-2086
    As the population grows in cities worldwide, the number of vehicles present on the roadways also increases, resulting in slow-moving and congested traffic. Therefore, a widespread problem in large cities concerns the traffic in the streets. Traffic signals are one of the most powerful tools available to city authorities for urban traffic control. Their proper installation can improve both traffic flow and the safety of all road users. Extensive research has been conducted to reduce the impacts of long car queues, based mainly on traffic signal timing optimization. This paper estimates the average waiting time at an isolated intersection and optimizes the timing of the green and red phases using an analysis of queueing systems. The control system is assumed to be the fixed-time type, and the Poisson process is considered for the arrivals. The proposed model is applied to real traffic data at a two-phase intersection in Bojnurd, Iran. It needs to be noted that the current situation at the intersection under study reduces average waiting time only for one side, but the analytic model can reduce average waiting time for the whole intersection. Moreover, simulation experiments are carried out, the results of which verify the capabilities of the proposed methodology in traffic signal control applications.
    Keywords: Traffic signal timing, Queueing system, Isolated intersection, Fixed-time control system
  • R. Ghasemi, Y. Azimi *, Z. Ghasemi Pages 2087-2096
    Ammonium Hydroxide production ‎unit (AHPU) is one of the widely ‎used and important units available in ‎many ‎industries such as oil and gas, ‎petrochemical, and power plants. In ‎this research, for the first time, a ‎detailed systematic inspection and ‎maintenance plan for AHPU ‎is ‎determined based on the ‎prioritization of equipment using ‎equipment’s risk analysis. ‎Equipment’s failure risk is ‎calculated ‎based on probability and ‎consequence of failure according to ‎American Petroleum Institute ‎Recommended Practice (API RP) 581. ‎Different ‎maintenance strategies were ‎designed and compared considering ‎several criteria like safety, cost, and ‎feasibility using the analytic hierarchy ‎process. Then risk-based optimal ‎maintenance policy for each group of ‎equipment ‎was identified. Finally ‎results showed that, the equipment ‎identified as high or medium to high ‎risk level such as liquid ‎ammonia ‎storage tank and its related ‎pipes, should has preventive ‎maintenance with an inspection ‎period of 48 months. While for the ‎medium risk equipment such as ‎ammonium hydroxide storage ‎tank ‎and low-risk equipment such as ‎ammonia absorption tank, should ‎have corrective maintenance with ‎inspection period of 72 and 90 ‎months, respectively‎.
    Keywords: Risk-based inspection, Analytic ‎Hierarchy Process, maintenance, Ammonium ‎Hydroxide
  • S.R. Karimpour, M.R. Besmi *, S.M. Mirimani Pages 2097-2106
    This paper proposes the optimal design process of an Interior permanent magnet synchronous generator (IPMSG) for wind power systems using the finite-element analysis (FEA). A multi-objective optimization design of PM generator based on Taguchi method is proposed. This paper takes the influence of the pole arc angle, magnet inset, magnet thickness, magnet width, stator tooth width and slot depth into consideration as a design parameters. The main characteristics of generator efficiency, torque ripple and output power are taken as optimization objectives. The orthogonal matrix is established according to the number of selected parameters and the level factor of each parameter and FEM is used to solve the experimental matrix. As a result, an improved generator was designed and selected, which had higher maximum output power and efficiency and lower torque ripple. Finally, a prototype IPMSG was manufactured based on analysis results and Taguchi method, and was tested. The experimental tests were conducted to verify the validity of the proposed design process and the effectiveness of the generator and as a result, perfectly cleared the optimization design.
    Keywords: Interior permanent magnet machine, Finite element method, multi-objective optimization design, orthogonal matrix, Taguchi method
  • H. Sanggoro *, S. Alisjahbana, D. Mohamad Pages 2107-2115
    Social conflict in projects is an uncompromising representation of differences in interests. Each project receives different claims from stakeholders based on their conditions. Project interest depends on the target level and goals to be achieved. Subsequently, the local community surrounding the project transforms their interests based on economic, social, cultural, and environmental expectations. This study aims to reveal factors of interests between project and local community on the occurrence of social conflict in projects. Soft System Methodology and CATWOE were used to identify root cause and factors of interests in the social conflict. Through library research and previous relevant researches, it was revealed that there are eight factors of interests which cause social conflict in projects. It is recommended that future researches should use factors in Formal System Methodology (FSM) to model the prediction of social conflict in projects based on different interests between project and local community. The results are useful to compose the standard environment and social framework (ESF) as a “middle way interests” concept to reduce social conflict in projects. By using the correct ESF, interests and conflicts can be managed well so that the benefits can be enjoyed by the community and project itself. Finally, the results of this study can be used to formulate indices of social conflicts in construction projects.
    Keywords: Social Conflict, middle way interests, Soft System Methodology, Local community, ESF
  • H. Bakhshandeh Amnieh *, S. M. M. Mirabedi, M. Rahmanpour, V. Jafari Pages 2116-2123
    Blasting is the initial stage of development in mining operations. Therefore, the use of explosives requires a technical design to control its adverse effects on nearby structures. In that regard, the blast vibrations in Izeh-Karun 3 main road project were recorded using four 3-component Blast Recorder seismographs. The seismographs recorded a peak particle velocity of 8.8 mm/sec in the nearby oil pipe. The blast pattern and the resulting ground vibration are simulated. The numerical model is verified using the recorded seismic data and the empirical model. The stresses applied on the oil pipeline were measured by the static analysis of the stress induced by the oil pipeline's internal pressure and the dynamic analysis of ground vibration. The pipeline stress was equal to 271 MPa, lower than the pipeline yield stress (414 MPa). Therefore, the vibrations induced by the blasting operation did not damage the oil pipeline. Comparing the vibration induced in the oil pipeline (8.8 mm/sec) with the critical vibration level (50 mm/sec) showed that the pipelines near the blast operation were at a safe distance.
    Keywords: blasting, ground vibration, numerical simulation
  • A. Zandvakili, N. Mansouri *, M. M. Javidi Pages 2124-2136
    Task scheduling is one of the fundamental issues that attract the attention of lots of researchers to enhance cloud performance and consumer satisfaction. Task scheduling is an NP–hard problem that is challenging due to the several conflicting objectives of users and service providers. Therefore, meta-heuristic algorithms are the more preferred option for solving scheduling problems in a reasonable time. Although many task scheduling algorithms are proposed, existing strategies mainly focus on minimizing makespan or energy consumption while ignoring other performance factors. In this paper, we propose a new task scheduling algorithm based on the Discrete Pathfinder Algorithm (DPFA) that is inspired by the collective movement of the animal group and mimics the guidance hierarchy of swarms to find hunt. The proposed scheduler considers five objectives (i.e., makespan, energy consumption, throughput, tardiness, and resource utilization) as cost functions. Finally, different algorithms such as Firefly Algorithm (FA), Particle Swarm Optimization (PSO), Grasshopper Optimization Algorithm (GOA), and Bat Algorithm (BA), are used for comparison. The experimental results indicate that the proposed scheduling algorithm can improve up to 9.16%, 38.44%, 3.59%, and 3.44% the makespan in comparison with FA, BA, PSO, and GOA, respectively. Moreover, the results show dramatic improvements in terms of resource utilization, throughput, and energy consumption.
    Keywords: Resource Utilization, Energy efficiency, Throughput, makespan, Latency, Meta-heuristic
  • M.M. Namar, O. Jahanian *, R. Shafaghat, K. Nikzadfar Pages 2137-2147
    Engine downsizing is a trusted method to reduce fuel consumption and pollution emitted from internal combustion engines. In this method, engine displacement volume is reduced while maintaining the same power/torque characteristics. However, there still exist several limitations to utilize this technology. In this paper, the naturally aspirated type of Iran national engine (EF7-NA) is investigated for a possible downsized version. A one-dimensional engine model equipped with a zero-dimensional two-zone combustion sub-model was developed and validated via experimental results for both natural aspirated and turbocharged engine types. Then experimental and numerical studies were carried out for the primary concept, deactivation of one cylinder besides using a turbocharger. To overcome the concept shortages, especially in lower ranges of engine speed, numerical studies were extended. Deployment of several turbochargers with different performance maps and different valve timing via a dual CVVT system were investigated. The results showed that there is a feasible method for EF7 engine downsizing via a 3-cylinder type equipped with a modified turbocharger and valve timing. The maximum difference between base-engine and downsized version torque is about 7% in low engine speeds.
    Keywords: Engine Downsizing, performance, 3-Cylinder, Turbocharger, CVVT
  • N. Jamali, A. Sadegheih *, M. M. Lotfi, H. Razavi Pages 2148-2156
    In this study, the anesthetic drug dose estimation due to the physiological patients' parameters is considered. The most critical anesthetic drug, propofol, is considered in this modeling. Among the intravenous anesthetic drugs, propofol is one of the most widely used during surgery in the induction and maintenance phase of anesthesia. The effect of propofol as an intravenous anesthetic agent is as well as sedate in/outside the operation theatres. In this work, the adaptive neuro-fuzzy inference system estimation model is applied to calculate the drug dose to administrate anesthesia safety. The model estimates the propofol dose during the induction phase based on the physiological parameters (age, weight, height, gender), blood pressure, heart rate, and the depth of anesthesia of real patients. The sensitivity analysis was applied to evaluate the validity of the estimation model, so the appropriate agreement is obtained. In the end, the proposed estimation model's performance is compared to the classical model and the actual data obtained from patients undergoing surgery. The results show that the ANFIS estimation model by 0.999 accuracies reduces the total amount of propofol dose. The proposed model not only controls the patient's depth of anesthesia accurately but also obtained outcomes in practice successfully.
    Keywords: Propofol dose, anesthesia, ANFIS, estimation model, Intravenous Anesthetic, Induction
  • A. Venkata Vishnu *, S. Sudhakar Babu Pages 2157-2166
    In order to minimise the difficulties associated in selecting conventional coolants in any machining, cutting fluids like vegetable based oils can serve as a viable alternative. Vegetable based oils when used in combination with eco-friendly techniques like MQL/NDM can have a major impact in any machining. In the present paper, performance characteristics of surface roughness and tool wear in machining of EN 36 steel alloy under Near Dry machining conditions/ Minimum quantity lubrication using vegetable based oil lubricant is studied. The input parameters like MQL flow rate, speed, feed and depth of cut for 5 levels are used in the CCD approach of Response surface methodology. For improving the machinability of alloy steel and to predit the values a regression equation is designed and developed between the input parameter and the output parameters. A multi-response optimum model for the output responses was also developed using RSM, GRA and JAYA algorithm, It was observed from the experiment results that JAYA algorithm has been proved the best multi-response optimization technique when compared to grey relational analysis and RSM.
    Keywords: Minimum Quantity lubrication, Vegetable based oil cutting fluids, Response Surface Methodology, Grey Relational Analysis, JAYA Algorithm
  • A. Norozpour Niazi, N. Vasegh *, A. A. Motie Birjandi Pages 2167-2179
    This paper proposes the improved hierarchical- based control of Microgrid based on proportional and multi-resonance controllers to compensate for harmonic distortion of nonlinear loads. Moreover, the probable transition of MG, especially from grid-connected to unplanned islanding and unintentional MG resources outage are studied. In current and voltage controllers of three-phase VSIs which are located in the inner level, the proportional and multi-resonant controllers are implemented. To attain proper decoupled (P-Q) power-sharing, a selective harmonic type virtual impedance, and a droop-based control are implemented at the primary level. Next, to reach better restoration and subsequently, seamless transition in accidental islanding, unintentional MG-DG’s outage, and synchronization process, the advanced three-phase SRF-PLL with in-loop MAF along with a simple adaptive lookup table are implemented in the secondary level of control. The MATLAB/Simulink simulation results verified that the proposed method improved the performance of control, effectiveness, and robustness in upstream or local grid variation.
    Keywords: Adaptive lookup table control, hierarchical control, Micro-grid, Nonlinear loads, Proportional, multi-resonance controller
  • S. Haghzad Klidbary *, M. Javadian, R. Omidi, R. P. R. Hasanzadeh Pages 2180-2188
    Utilizing fuzzy techniques, especially fuzzy type-2, is one of the most widely used methods in machine learning to model uncertainty. In addition to algorithm provision, the hardware implementation capability, and proper performance in real-time applications are other challenges. The use of hardware platforms that have biological similarities and are comparable to human neural systems in terms of implementation volume has always been considered. Memristor is one of the emerging elements for the implementation of fuzzy logic based algorithms. In this element, by providing current and selecting the appropriate direction for the applied current, the resistance of the memristor (memristance) will increase or decrease. Various implementations of type-1 fuzzy systems exist, but no implementation of type-2 fuzzy systems has been done based on memristors. In this paper, memristor-crossbar structures are used to implement type-2 fuzzy membership functions. In the proposed hardware, the membership functions can have any shape and resolution. Our proposed implementation of type-2 fuzzy membership function has the potential to learn (On-Chip learning capability regardless of host system). Besides, the proposed hardware is analog and can be used as a basis in the construction of evolutionary systems. Furthermore, the proposed approach is applied to memristor emulator to demonstrate its correct operation.
    Keywords: Fuzzy inference system, Fuzzy Membership Function, Type-1 Fuzzy (T1F), Type-2 Fuzzy (T2F), Hardware Implementation, Memristor-Crossbar Structures
  • K. Kusmono *, C. Bora, U. Salim Pages 2189-2197
    In the present study, the influences of cold rolling and annealing time on the fatigue crack propagation behavior of AA5052 aluminum alloy were investigated. The alloy sheet was cold-rolled under different rolling reductions, i.e., 0, 15, 30, and 45%. 45% as-rolled specimen was then annealed at 370°C under different annealing times, i.e., for 2, 4, and 6 h. The microstructure evolutions after the cold rolling and annealing treatments were also examined using optical microscopy whereas the fatigue crack propagation behavior was characterized by using a fatigue test. Results showed that severely elongated grains were observed with increasing the rolling reduction. The elongated microstructures were changed into equaxial structures due to recrystallization during annealing treatment. The fatigue life was decreased drastically by increasing the rolling reduction but increased significantly with increasing annealing time. The fatigue life of the alloy was reduced by 93% when cold-rolled up to 45%. On the other hand, the fatigue life of the 45% rolled samples was increased significantly by 412% when annealed at 370ºC for 6 h.
    Keywords: AA 5052 aluminum alloy, Cold rolling, Annealing, fatigue resistance