International Journal of Engineering Research in Africa最新文献_第7页

Combined Thermal Performance Enhancement of Parabolic Trough Collectors Using Alumina Nanoparticles and Internal Fins 利用氧化铝纳米颗粒和内翅片复合增强抛物槽集热器的热性能

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International Journal of Engineering Research in Africa Pub Date : 2022-11-23 DOI: 10.4028/p-63cdb1

Mohamed H. Yehia, Muhammed A. Hassan, Nabeel Abed, A. Khalil, N. Bailek

{"title":"Combined Thermal Performance Enhancement of Parabolic Trough Collectors Using Alumina Nanoparticles and Internal Fins","authors":"Mohamed H. Yehia, Muhammed A. Hassan, Nabeel Abed, A. Khalil, N. Bailek","doi":"10.4028/p-63cdb1","DOIUrl":"https://doi.org/10.4028/p-63cdb1","url":null,"abstract":"Parabolic trough collectors are the currently dominant technology for concentrated solar power systems, employed to produce thermal energy at low to medium temperatures (up to 400°C). Extensive research has been carried out to enhance the thermal efficiency and reduce the power production costs of these concentrators. However, there is a lack of studies on combined passive performance enhancement using alternative fluids and absorber designs. In this study, the thermal performance of a full-sized parabolic trough collector is analyzed with the presence of internal longitudinal fins in combination with the use of oil-based nanofluid (Al2O3-Syltherm 800) of different volume fractions. The governing equations are numerically solved using ANSYS FLUENT 17.1 software and the Monte-Carlo ray-tracing (MCRT) model was used to apply the non-uniform heat flux profile over the external surface of the solar receiver. The results show that both techniques enhance thermal energy utilization and reduce radiative and convective thermal losses, resulting in higher thermal efficiency, but also larger pressure losses. The thermal performance is enhanced by 0.1-1.16 % with nanofluid, up to 6.8 % with internal fins, and by up to 7.25 % when both techniques are adopted. These enhancements are attributed to the reduced mean circumferential temperature of the absorber tube.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48493740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Static and Dynamic Analysis of Keddara Dam 克达拉大坝静动力分析

IF 0.7

International Journal of Engineering Research in Africa Pub Date : 2022-11-23 DOI: 10.4028/p-81xn1p

Samya Chebout, R. Bahar

引用次数: 0

A Low-Cost Control Architecture for Buck Converter Fed VSI Based BLDC Motor Drive 基于Buck变换器的无刷直流电机驱动的低成本控制体系

IF 0.7

International Journal of Engineering Research in Africa Pub Date : 2022-11-23 DOI: 10.4028/p-34izda

M. Kurre, S. Deshmukh, Rajdeep Tandekar, Pratikanta Mishra, A. Banerjee

{"title":"A Low-Cost Control Architecture for Buck Converter Fed VSI Based BLDC Motor Drive","authors":"M. Kurre, S. Deshmukh, Rajdeep Tandekar, Pratikanta Mishra, A. Banerjee","doi":"10.4028/p-34izda","DOIUrl":"https://doi.org/10.4028/p-34izda","url":null,"abstract":"In this paper, a novel low-cost digital controller to drive a buck converter fed voltage source inverter (VSI) based brushless DC (BLDC) machine has been proposed. This controller is designed to be implemented solely in digital platforms and has multiple numbers of predefined discrete duty ratios. In conjunction with buck converter fed VSI, the controller is beneficial to enhance the speed and resultant torque profile of BLDC motor drive as compared to conventional bang-bang or on-off controller. The controller also incorporates a current limiter to avoid the over-current loading of the motor. The sampling time and the design of the current limiter are mathematically derived in the paper. The working efficiency of the developed controller for the BLDC motor drive has been examined for various vital and steady-state conditions. The speed ripples, settling time, tolerance to the commanded speed, and load variations are validated and presented in this paper. The proposed controller has been performed and implemented in the field-programmable gate array platform and compared to generic pre-existing controllers to validate the cost-effectiveness of the controller.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46956728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Selection of a Pavement Structure from Technically Established Alternatives Based on Construction Cost, Energy Consumption, and Carbon Footprint 基于施工成本、能源消耗和碳足迹从技术上确定的替代方案中选择路面结构

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International Journal of Engineering Research in Africa Pub Date : 2022-11-23 DOI: 10.4028/p-xx05a5

Wissem Taktak, A. Loulizi

{"title":"Selection of a Pavement Structure from Technically Established Alternatives Based on Construction Cost, Energy Consumption, and Carbon Footprint","authors":"Wissem Taktak, A. Loulizi","doi":"10.4028/p-xx05a5","DOIUrl":"https://doi.org/10.4028/p-xx05a5","url":null,"abstract":"This paper presents a procedure to select a pavement structure from technically established alternatives. The general proposed process relies on calculating the present worth of total cost resulting from construction, maintenance/rehabilitation, energy consumption and carbon footprint during those activities as well as recycling of the materials at their end life. However, depending on data availability, the general process could be reduced to just the construction phase as is the case in most developing countries where required pavement performance data is scarce. The reduced procedure was validated on four types of pavements for six traffic levels and three subgrade types. Under the conditions considered in this study, it was found that concrete pavements have high construction, embodied energy, and carbon footprint costs (the environmental impact represents about 66% of the total cost) as compared to other pavement types. Full-depth asphalt pavements were found to be the best ecological type, their construction cost is a little higher than the environmental one with a distribution of about 53% and 47%, respectively. Inverted pavements seem to be a good alternative to weak subgrades although the costs associated with environmental effects contribute to about 52% of the total cost.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47423300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Pilot Implementation of Innovative Proposal for Service Level Improvement in a Spare Parts Trading Company 改进服务水平创新方案在某备件贸易公司的试点实施

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International Journal of Engineering Research in Africa Pub Date : 2022-11-23 DOI: 10.4028/p-70sd0q

Emma Ramos-Valle, André Paulino, Pedro Chavez, J. Alvarez, S. Nallusamy

{"title":"Pilot Implementation of Innovative Proposal for Service Level Improvement in a Spare Parts Trading Company","authors":"Emma Ramos-Valle, André Paulino, Pedro Chavez, J. Alvarez, S. Nallusamy","doi":"10.4028/p-70sd0q","DOIUrl":"https://doi.org/10.4028/p-70sd0q","url":null,"abstract":"In the context in which spare parts trading companies are becoming increasingly competitive, the level of service is essential to be able to compete in the market. This indicator is affected by on-time deliveries, which are a key factor in meeting customer demand, as this determines customer satisfaction and thus has an effect on the company's profitability. For a company to deliver its products on time, the warehouse processes must work efficiently, making the picking process one of the most critical of them. It must also run a proper inventory procurement process in order to have stock on hand to fulfill customer orders. This case study focuses on increasing the level of service in a company that sells spare parts for mining, which was found to have a low service level of 66.1%, in contrast to the recommended level for the sector, which is 85.9%. Therefore, the implementation of the 5S methodology, Systematic layout planning, demand forecasting, and cycle counting are proposed as tools to solve the root causes of the problem. The main results indicated a reduction in picking times of 36.70%, an increase in demand forecast accuracy of 13.45%, and an increase in Inventory Record Accuracy (IRA) of 5.42%.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47624216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Damping Subsynchronous Oscillations Using a High Voltage Direct Current-Based Multi-Modal Damping Controller 基于高压直流的多模态阻尼控制器抑制次同步振荡

IF 0.7

International Journal of Engineering Research in Africa Pub Date : 2022-11-23 DOI: 10.4028/p-530sb3

C. B. Tambwe, R. P. Carpanen

{"title":"Damping Subsynchronous Oscillations Using a High Voltage Direct Current-Based Multi-Modal Damping Controller","authors":"C. B. Tambwe, R. P. Carpanen","doi":"10.4028/p-530sb3","DOIUrl":"https://doi.org/10.4028/p-530sb3","url":null,"abstract":"Conventional series capacitors in transmission lines are of paramount importance for enhancing power transfer capability. However, the major drawback of series capacitors is the induced subsynchronous resonance phenomenon in power systems. This phenomenon affects nearby turbogenerator shafts and severely limits their reliability. Also, the controls of High Voltage Direct Current links are considered as a potential source of subsynchronous oscillations. This paper investigates the performance of a multimodal damping controller to stabilize unstable torsional modes in combination with a Power System Stabilizer for inertial mode damping. This research uses time-domain simulation-based multimodal damping controller design methods, namely the test signal and phase correction methods. These two methods involve injecting a test signal at a frequency of interest into the rectifier current control loop and measuring its phase difference with the electromagnetic torque, thus providing corresponding compensators to minimize the resulting angle. This work uses Power System Computer-Aided Design for time-domain simulation and Fast Fourier Transforms Analysis to conduct the phase correction method and verify controller performance.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41405592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prediction of the Hardness of Pulverized Glass Waste-Reinforced Aluminium Alloy 6061-T6 Friction Stir Welded Joint 玻璃渣增强6061-T6铝合金搅拌摩擦焊接接头硬度预测

IF 0.7

International Journal of Engineering Research in Africa Pub Date : 2022-11-23 DOI: 10.4028/p-j02z6p

T. Abioye, Ebenezer Olanipekun, A. S. Anasyida

{"title":"Prediction of the Hardness of Pulverized Glass Waste-Reinforced Aluminium Alloy 6061-T6 Friction Stir Welded Joint","authors":"T. Abioye, Ebenezer Olanipekun, A. S. Anasyida","doi":"10.4028/p-j02z6p","DOIUrl":"https://doi.org/10.4028/p-j02z6p","url":null,"abstract":"The purpose of this study is to investigate the friction stir weld quality of pulverized glass waste (PGW)-reinforced AA6061-T6 and develop a model predicting the hardness of the joint. Friction stir welding of PGW-reinforced AA6061-T6 was done within a process window. The process was optimized for the maximum joint hardness. Thereafter, the result of the hardness was used to develop a model using a novel statistical analytical technique. The addition of PGW enhanced the AA6061-T6 friction stir welded joint hardness. The maximum hardness (112 HV) of the PGW-reinforced joint, which was obtained at optimal setting of 900 rpm rotational speed, 40 mm/min traverse speed and 1o tilt angle, is by a factor of 1.72 greater than the unreinforced joint and close to the hardness of the as-received AA6061-T6 (120 HV). The developed model can predict the hardness of the PGW-reinforced AA6061-T6 joint up to an accuracy of 89%. The model shows that the rotational speed, tilt angle and their interaction contributed significantly to the hardness of the PGW-reinforced AA6061-T6 friction stir welded joint. This model is suitable for determining the hardness property of particle-reinforced AA6061-T6 friction stir welded joint at varying processing parameters.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48225788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of Waste Glass Powder on Properties of Self-Compacting Repair Mortars 废玻璃粉对自密实修补砂浆性能的影响

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International Journal of Engineering Research in Africa Pub Date : 2022-11-23 DOI: 10.4028/p-1eiar8

A. Benyahia, M. Salhi, Toufik Boubekeur

引用次数: 0

Spark Plasma Sintering of Dinickel Boride Reinforced Titanium Matrix Composites 火花等离子烧结硼化镍增强钛基复合材料的研究

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International Journal of Engineering Research in Africa Pub Date : 2022-11-23 DOI: 10.4028/p-yf11lk

O. Ayodele, P. Olubambi

引用次数: 1

Characterization of Amuda-Isuochi Nigerian Clay Deposit for Potential Industrial Applications Amuda Isuochi尼日利亚粘土矿床的特征及其潜在的工业应用

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International Journal of Engineering Research in Africa Pub Date : 2022-11-23 DOI: 10.4028/p-339x01

N. Uwaezuoke, V. Okoro, K. Igwilo, S. Onwukwe, K. C. Iwuanyanwu, Victor C. Ayogu

引用次数: 1