International Journal of Mechanical Engineering and Applications最新文献

{"title":"Numerical Estimation of Heat Recovery within a Distributed Incinerator Using Water and Hydrocarbons as Working Fluids","authors":"H. Yamashiro, T. Yara, Kenji Fukutomi","doi":"10.11648/J.IJMEA.20190701.12","DOIUrl":"https://doi.org/10.11648/J.IJMEA.20190701.12","url":null,"abstract":"The potential of a cogeneration system combined with a small combustion furnace was investigated in this study. The heat transfer between the exhaust gas and working fluid flowing in a spiral tube heat exchanger was estimated numerically and the amount of vapor generated was predicted. The combustion chamber had a 0.49 m3 inside volume with a chimney height of 2.5 m and an inner diameter of 0.28 m. A uniform gas side temperature condition that was referenced from the results of a preliminary experiment and a computational fluid dynamics simulation were adopted to simplify calculations and clarify the effects of working fluids. The amounts of heat recovery when utilizing water and other types of working fluids (Pentane, Butane) were compared. The most effective tube length considering pressure drop and phase change was also predicted. Isentropic theoretical thermal efficiency and T-s diagrams are analyzed to evaluate the vapor-power conversion rate using waste heat. As a result, a potential the heat recovery rate of approximately 100 kW at a 150 kg/h mass flow rate is expected.","PeriodicalId":398842,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123851041","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}

{"title":"Numerical Analyses on Liquid-Metal Magnetohydrodynamic Flow in 180°-Turn Channel","authors":"H. Kumamaru, N. Takagaki","doi":"10.11648/J.IJMEA.20190701.11","DOIUrl":"https://doi.org/10.11648/J.IJMEA.20190701.11","url":null,"abstract":"Numerical calculations have been performed on liquid-metal magnetohydrodynamic (MHD) flow in a 180°-turn (i.e. hairpin-shaped) channel, in order to contribute to design of a fusion reactor blanket. A magnetic field is applied in a direction perpendicular to an inlet channel, a turning channel (turning section) and an outlet channel. The continuity equation, the momentum equation and the induction equation have been solved numerically. In this study, attention is focused on pressure drops along the channels and pressure distribution in the turning channel. The Hartmann number (indicating magnetic field strength), the Reynolds number and the channel aspect ratio, in the present calculations, cover 100 to 500, 1000 to 5000 and 1 to 1/4, respectively. The following things have become clear from calculation results. The total MHD pressure drop from a channel inlet to a channel outlet agrees approximately with that for the total channel length, meaning that the loss coefficient for the turning channel is nearly zero or small. For large Reynolds numbers, the pressure in the peripheral region of the turning channel becomes larger than that at the channel inlet, due to the centrifugal force acting in the turning channel. It is considered that this pressure increase should be taken into account in designing a fusion reactor blanket.","PeriodicalId":398842,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114441140","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}

{"title":"Solidification and Filling Related Defects Analysis Using Casting Simulation Technique with Experimental Validation","authors":"Nazma Sultana, M. Rafiquzzaman, Younosur Rahman, A. Das","doi":"10.11648/J.IJMEA.20180606.12","DOIUrl":"https://doi.org/10.11648/J.IJMEA.20180606.12","url":null,"abstract":"Solidification as well as filling has great influences on the quality of cast products. In modern competitive world for increasing the quality of products these two steps draw higher attention to casting engineers. This case study is just one of the followings of the above mentioned objective. The aim of the present work is to reduce the rejection rate of cast products in a foundry shop due to casting defects in sand casting process using a computer aided simulation technique. In general conventional techniques require a larger number of trials with higher costs for checking outputs when the number of process parameters increase that can be reduced using simulation. For the simplification in this analysis grain size of sand, material quality, casting process parameters are considered uniform for all cases. Only the positional and dimensional variances are taken in considerations for defects analysis. It is found that defects such as shrinkage porosity, improper solidification, air entrapment, mould erosion are directly related with gating and feeding system design and although other process parameters are considered uniform but this defects will be changed with changing the design parameters. In this case Click2cast casting simulation software is used for mould filling and solidification analysis and it is observed that proposed gating and feeding system design improves casting yield approximately 15% more than conventional gating and feeding system. The validation of simulation is proved through experimental trials in foundry shop.","PeriodicalId":398842,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"2013 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114589830","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}

{"title":"Oromia Forest Industry’s Supply Chain Network Performance Analysis","authors":"Hiluf Reda, B. Beshah","doi":"10.11648/J.IJMEA.20180606.11","DOIUrl":"https://doi.org/10.11648/J.IJMEA.20180606.11","url":null,"abstract":"Supply chain network performance measurement is the process of qualifying the efficiency and effectiveness of the supply chain. Supply chain network performance analysis is one of the promising tools employed for assessing performance and then taking the necessary measures for improvements of existing supply chain network. Ethiopia’s forest coverage is estimated about 10 to 30 percent. Still there are efforts to increase the coverage. Reducing deforestation has equal importance with that of increasing plantation to improve forest coverage in the country. For instance, in order to reduce deforestation the government has put in place a policy to import wood and wood products without tax. However, if the forests are not properly cultivated or harvested then forests will decay and also triggers illegal users which intern will have impact on the forests coverage in the country. In this study, Oromia Regional State which covers 70% of the total forest coverage in the country is considered and the research identified that forests are decaying in the region. This is partly because the major customers are far from the forests. Hence, the forest products supply chain network is first analyzed. For this purpose, main sources of data were interview, observations, secondary data, Geographic Information System (GIS), and standard preference table. Based on the findings a new supply chine network is designed which enables the Oromia Forests Industry optimally utilizes its resources and at the same time address customers’ requirements keeping the current forest as well as improving forest coverage of the region.","PeriodicalId":398842,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133269346","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}

{"title":"Heat Transfer and Friction Factor Characteristics in Twisted Square Ducts","authors":"Madugula Udaya Kumar, Mohammed Yeakub Ali","doi":"10.11648/J.IJMEA.20180605.11","DOIUrl":"https://doi.org/10.11648/J.IJMEA.20180605.11","url":null,"abstract":"The present work experimental and numerical investigations have been carried out to study friction factor and heat transfer characteristics of twisted square ducts. Experiments were conducted for different velocities of air under constant heat flux condition, twist ratio is equal to 6.12 and also Reynolds number varied from 8000 to 30000. The experimental analysis has been carried out and the experimentation is completely based upon design of experiments to get the optimum heat transfer rate and minimize pressure drop. The results of friction factor, Nusselt number and thermal performance factor are presented. Twisted square duct shows relatively higher heat transfer and optimum pressure drop compared to plain square duct. The experimental results shows that Nusselt number for the twisted square duct is about 1.89 times above that for the plain square duct while friction factor is 2.29 times higher (f/fo= 2.29). Thermal performance (enhancement ratio) of the twisted square duct is 1.41. In this work Numeric simulations were calculated by using the CFD software package ANSYS 18.2 FLUENT has been used. Heat transfer and numerical flow behaviors such as temperature, friction factor contours of the are also reported. Hence it is concluded that square duct with twist ratio 6.12 gives highest heat transfer and thermal performance due to lowest friction loss indicating promising device of the twisted square duct.","PeriodicalId":398842,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131813149","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}

{"title":"A Prediction Method for Galloping of Transmission Lines Based on Improved Neural Network","authors":"Yongfeng Cheng, Jingshan Han, B. Liu, Danyu Li","doi":"10.11648/j.ijmea.20180604.15","DOIUrl":"https://doi.org/10.11648/j.ijmea.20180604.15","url":null,"abstract":"The traditional back-propagation neural network (BP) have the disadvantages including the random generation of initial weights and thresholds, easy to fall into the local optimization, and the convergence speed is slow, and it’s hard to confirm the number of neurons in hidden layer. In this paper, the Genetic Algorithm (GA) is utilized to optimize the initial weights and thresholds space of the BP neural network. To obtain the optimal weight matrix and threshold matrix, the error-forward-feedback neural network training is carried out by using the data of transmission line galloping. The trial and error method are used to reduce the number of hidden layer neurons and find the optimal number of neurons. An optimized GA-BP neural network model is established to warn the occurrence of transmission line galloping. The historical data of the transmission lines galloping in the related areas is analyzed by the optimized GA-BP neural network model. The validity and practicability of the proposed GA-BP neural network model is tested and verified. The simulation results show that the GA-BP neural network module could predict the galloping situation of transmission lines more accurately and effectively. As a result, it provides a strong guarantee for preventing large-scale grid fault disasters, and further improves the power grid's ability to withstand natural disasters.","PeriodicalId":398842,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126902945","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}

{"title":"Study on the Influence of Geometric Shape of Material on the Reposed Angle Based on EDEM","authors":"Xu Lin, Yanhui Chen","doi":"10.11648/J.IJMEA.20180604.14","DOIUrl":"https://doi.org/10.11648/J.IJMEA.20180604.14","url":null,"abstract":"When studying the discreteness of granular materials, the size of the angle of repose can be used as an important parameter to study the stability of granular materials. In recent years, many scholars have studied the morphology of particles, but they are basically based on the regular shape of spheres and ellipsoids, which are very different from the actual particle shape, which leads to the measurement results not consistent with the actual results. Therefore, based on the above reasons, this paper mainly studied the influence of geometric shape for the Reposed Angle, the simulation experiment is carried for the Reposed Angle using the discrete element software EDEM, the Reposed Angle is measured for five different shape using slice cutting analysis method, and the experimental measurement has carried on for the Reposed Angle for each shape, SPC method is used to determine the reliability of the data. The results show that the size of the Reposed Angle increases gradually in the order of sheet, intermediate, horn, strip and equal square among the five studied shape, the mechanism is that the greater the number of internal contact is, can truly reflect the interaction and occlusal relationship, the more easily locked the particles are in the force chain, the more difficult to separate the particles are, the more stable the accumulation characteristics are.","PeriodicalId":398842,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116774367","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}

{"title":"The Influences of Air Intake Temperature on the Gasoline Engine’s Otto Cycle","authors":"Feng Liu","doi":"10.11648/J.IJMEA.20180604.13","DOIUrl":"https://doi.org/10.11648/J.IJMEA.20180604.13","url":null,"abstract":"This thesis is about the calculations and researches of the improved coolant system of turbocharged gasoline engine, it introduces the basic concept of gasoline engine’s turbo technology, and shows the detailed information and parameters of 486 turbocharged gasoline engine, established the formulas of the Otto cycle and its relevant parameters, emphasized to analyze the influences of the intake air temperature on the engine’s Otto cycle. The effects of the turbo gasoline intake temperature mainly contains 2 points: the outlet temperature of the turbo and the temperature decline effect of the coolant system; This thesis compares the effects of gasoline’s Otto Cycle which configures or not with a middle cooler, utilized a thermal dynamics calculation method to research, calculate and analysis the parameters of the turbocharged engine’s Otto cycle, the results are corresponding with the experiment(the thermal balance experiment), the property indices are included circulate thermal efficiency, exergy efficiency and average valid pressure. Through the contrasts and analysis, it obviously shows that, with the middle coolant, it has an advantage in the average valid pressure, intake temperature, and exergy efficiency. Absolutely it is necessary and efficient configured with middle coolant on the turbocharged gasoline engine.","PeriodicalId":398842,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128998186","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}

{"title":"The Solution of the Overvoltage Damage for IMS’s Microseismic Monitoring System","authors":"Chen Ruxiu, Li Hua","doi":"10.11648/J.IJMEA.20180604.12","DOIUrl":"https://doi.org/10.11648/J.IJMEA.20180604.12","url":null,"abstract":"With the further development of digitized mine system construction, various kinds of communication，information，automatic and intelligent electronic equipment are widely used in mines. Due to the harsh underground environment of domestic (China) mines, various faults of electronic equipment occur frequently, such as dampness, dust pollution, burn damage, mechanical damage. This makes the system can not run stably and reliably. Especially the phenomenon of burning damage of electronic equipment. It is often large area damage when it happens, which seriously affects the safety production of enterprises. The IMS equipment of microseismic monitoring system that installed in Shizhuyuan Mine was burning damaged many times. Through the in-depth analysis and diagnosis of the failure of the IMS burning module and the overall microseismic monitoring system underground chamber, the fault (which is the system overvoltage) and its causes are found out. According to the reality condition of Shizhuyuan mine that how to prevent the overvoltage damage is systematic analysis and improvement. Than adopt effective measure and methods such as: prevention of overvoltage generation, cut off the intrusion pathway of overvoltage, choosing the surge protector reasonably with the insulation level of the system, switch to the right power supply plan and power supply facilities. These protective measures and methods comprehensively protect the safety of microseismic monitoring system equipment. After that, the microseismic monitoring system is successfully protected and no longer burned down. It successfully solves the problem of equipment burning damage of microseismic monitoring system, provides reliable guarantee for mine safety production. Shizhuyuan mine is a typical underground mining metal ore in China, the successfully solution of overvoltage damage provides a good demonstration for how to prevent mine electronic equipment underground from burning damage, It also provides more standardized and accurate requirements for the way and the protection of power supply system, and the laying of lines for a new projects.","PeriodicalId":398842,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131060149","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}

{"title":"Design and Prototyping of Teff (ጤፍ) Row Planter and Fertilizer Applier","authors":"Tesfaye Gonite, Hiluf Reda","doi":"10.11648/J.IJMEA.20180604.11","DOIUrl":"https://doi.org/10.11648/J.IJMEA.20180604.11","url":null,"abstract":"Teff is one of the most grown crops and a preferable food in Ethiopia. Wholesale prices for Teff are relatively high, making the crop attractive to some producers as a cash crop, production costs are also high, implying fertilizer prices and the labor-intensive nature of the crop. Now a daysteff got attention of international market. But, productivity yields are relatively low (around 1.2 tones/ha) and suffer from high loss rates (25-30% both before and after harvest). Respective bodies tried to take different actions to improve the productivity of teff. It has been argued recently that low teff productivity is partly caused by the way farmers sow teff seed; broadcasting teff seed by hand using a rate of 25–50 kg per hectare. Researchers approved reducing the seed rate to between 2.5 and 3 kg per hectare by row planting allows for reduced competition between seedlings and optimal tillering of the teff plants. This study was aimed to design and prototyping of teff row planter and fertilizer applier. It will improve productivity of teff and reduces cost of teff production process. Literature review and visiting of existing teff row planter machines, conceptual and embodiment design procedures, modeling machine components by solid work software, manufacturing the components and assembling of machine in Debre Berhan university manufacturing workshop, testing the applicability of machine on farm were used as methodology. The metering of teff and the locomotion mechanism of the machine has given more emphasis through the design and manufacturing process. The researchers designed ten rows planter. Due to lack of appropriate manufacturing machine and material, actually obtained a machine which can plant six rows in one trip. For better result and applicability, components should produce with appropriate machine and from appropriate material. some shaking mechanism also recommended for better performance.","PeriodicalId":398842,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"181 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123496991","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}