Pub Date : 2020-07-01DOI: 10.13189/ujme.2020.080401
Pantira Klankaew, Kaboon Thongtha, Siripawn H Winter, Pornchai Chaisanit, K. Kumnungkit, N. Pochai
Oil skimmer is a useful tool in recovering all types of floating waste oils, greases and fats from water surfaces. Lubricant film flow velocity approximation is an important problem of oil skimmer belt speed adjustment. The adjustment belt speed level is up to several physical parameters of oil types. A thin lubricant film flow velocity on a moving belt oil skimmer can be modeled in a form of a nonlinear differential equation as a boundary value problem. The model is providing the lubricant film flow velocity in each thickness layers. In this research, a centered in space finite difference method and a Quasi-Newton iterative method are proposed to approximate the solutions of the nonlinear thin lubricant film flow velocity model. Their numerical simulations of a thin lubricant film flow velocity on a moving oil skimmer belt with varied physical parameters are investigated. The proposed numerical techniques give good agreement approximated solutions in several moving belts speed levels with the external force factor. These are then useful to achieve the optimum belt oil skimmer speed for each lubricant type.
{"title":"A Mathematical Model of Lubricant Film Flow Velocity on a Belt Type Oil Skimmer in a Part of Wastewater Treatment Process Using a Finite Difference Method with Quasi-Newton Iterative Technique","authors":"Pantira Klankaew, Kaboon Thongtha, Siripawn H Winter, Pornchai Chaisanit, K. Kumnungkit, N. Pochai","doi":"10.13189/ujme.2020.080401","DOIUrl":"https://doi.org/10.13189/ujme.2020.080401","url":null,"abstract":"Oil skimmer is a useful tool in recovering all types of floating waste oils, greases and fats from water surfaces. Lubricant film flow velocity approximation is an important problem of oil skimmer belt speed adjustment. The adjustment belt speed level is up to several physical parameters of oil types. A thin lubricant film flow velocity on a moving belt oil skimmer can be modeled in a form of a nonlinear differential equation as a boundary value problem. The model is providing the lubricant film flow velocity in each thickness layers. In this research, a centered in space finite difference method and a Quasi-Newton iterative method are proposed to approximate the solutions of the nonlinear thin lubricant film flow velocity model. Their numerical simulations of a thin lubricant film flow velocity on a moving oil skimmer belt with varied physical parameters are investigated. The proposed numerical techniques give good agreement approximated solutions in several moving belts speed levels with the external force factor. These are then useful to achieve the optimum belt oil skimmer speed for each lubricant type.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121534610","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}
Pub Date : 2020-07-01DOI: 10.13189/ujme.2020.080404
Abdullah A. Alghafis, E. A. Raouf, Abdumalik Aldahlawi, Faisal Alassaf, Abdulmajeed Alrsheedi, Amer Alharbi
Turbochargers is used on several engines since 1962, to gain greater power output. This paper presents a study of the impact of the turbocharger pressure ratio on diesel engine performance and nitrogen oxides (NOX) emissions. A series of simulation experiments were carried out by using Diesel-RK software on variable turbocharger pressure ratio diesel engine. Diesel-RK is known as a very good open source software for youthful researchers, since it is free and talented of simulating combustion and thermodynamics of diesel engines very well. The simulated results showed that, turbocharger pressure ratio (PR) is an important parameter which affects directly on engine performance, engine brake power (BP) increased when pressure ratio increased. At 2500rpm and pressure ratio equal to 1.5 the BP increment about 27.4% when compared to natural aspirated (NA) engine. More increment about 55% is achieved by increasing the pressure ratio to 2.5. Though the specific fuel consumption (SFC) reduced as the pressure ratio increased. At 4000rpm and pressure ratio equal to 1.5 the SFC reduction about 5% when compared to NA engine. More decrement rate in the SFC rate about 7% is achieved by increasing the turbocharger pressure ratio to 2.5. The brake thermal efficiency (BTE) also increased as the pressure ratio increased, due to increase in power. At NA engine and 3000rpm, the BTE is found to be 32.5%, while at PR = 1.5, the BTE is equal to 33.9% and the BTE at the PR equal to 2.5 is increased to 33.8%. On the other hand engine NOx emissions increased as the pressure ratio increased, at 3000rpm and PR equal to 1.5, the NOX rate increased at a rate of 20% when compared to the emissions of NA engine. NOX emissions continuously increased and reached more than 42% with PR equal to 2.5 when compared to NA engine. Turbocharger gives the small displacement engines much more power relative to their size e.g. PR equal to 2.5, turbochargers run off energy of exhaust gases that is always lost by the NA engines, so the recovery of this energy develops the engine efficiency.
{"title":"Impact of Turbocharger Compressor Pressure Ratio on Diesel Engine Performance and Nitrogen Oxides Emissions","authors":"Abdullah A. Alghafis, E. A. Raouf, Abdumalik Aldahlawi, Faisal Alassaf, Abdulmajeed Alrsheedi, Amer Alharbi","doi":"10.13189/ujme.2020.080404","DOIUrl":"https://doi.org/10.13189/ujme.2020.080404","url":null,"abstract":"Turbochargers is used on several engines since 1962, to gain greater power output. This paper presents a study of the impact of the turbocharger pressure ratio on diesel engine performance and nitrogen oxides (NOX) emissions. A series of simulation experiments were carried out by using Diesel-RK software on variable turbocharger pressure ratio diesel engine. Diesel-RK is known as a very good open source software for youthful researchers, since it is free and talented of simulating combustion and thermodynamics of diesel engines very well. The simulated results showed that, turbocharger pressure ratio (PR) is an important parameter which affects directly on engine performance, engine brake power (BP) increased when pressure ratio increased. At 2500rpm and pressure ratio equal to 1.5 the BP increment about 27.4% when compared to natural aspirated (NA) engine. More increment about 55% is achieved by increasing the pressure ratio to 2.5. Though the specific fuel consumption (SFC) reduced as the pressure ratio increased. At 4000rpm and pressure ratio equal to 1.5 the SFC reduction about 5% when compared to NA engine. More decrement rate in the SFC rate about 7% is achieved by increasing the turbocharger pressure ratio to 2.5. The brake thermal efficiency (BTE) also increased as the pressure ratio increased, due to increase in power. At NA engine and 3000rpm, the BTE is found to be 32.5%, while at PR = 1.5, the BTE is equal to 33.9% and the BTE at the PR equal to 2.5 is increased to 33.8%. On the other hand engine NOx emissions increased as the pressure ratio increased, at 3000rpm and PR equal to 1.5, the NOX rate increased at a rate of 20% when compared to the emissions of NA engine. NOX emissions continuously increased and reached more than 42% with PR equal to 2.5 when compared to NA engine. Turbocharger gives the small displacement engines much more power relative to their size e.g. PR equal to 2.5, turbochargers run off energy of exhaust gases that is always lost by the NA engines, so the recovery of this energy develops the engine efficiency.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115245023","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}
Pub Date : 2020-07-01DOI: 10.13189/ujme.2020.080406
M. Lee, Pui San Lee
This study aims to design and develop a size segregation sieve machine that utilizes centrifugal action to separate impurities from short Oil Palm Frond (OPF) fibers. OPF fibers can manufacture into various products such as erosion control mat and medium density fibreboard as an agricultural waste management program for achieving environmental sustainability. In this aspect, the role of the fiber sieving machine would be significant to support the industry in the production of OPF fibers. However, a thorough literature survey reviewed that limited publications are available in this area; most work done is published in the form of patents. In addition, most fiber sieving machines available in the market utilize manual labour work in the separation phase, where they are highly inefficient. Therefore, this study is designed to fill these gaps. The design of this study adopts the mechanism of various size segregation concepts available and includes centrifugal action in the separation process to increase efficiency. Eventually, a prototype was fabricated for laboratory testing. Several vital parameters are highlighted, which includes mesh surface inclination, sieving duration, a rotation speed of screen and maximum capacity that significantly affects the sieving efficiency. Findings from this study show that sieving duration is less significant to the developed design as higher rotation speed will tend to improve the passing percentage of the fibers. Testing results also revealed the potential application of such a machine in other particle separation applications such as soil separation. For future study, it is recommended to improve the current design in terms of parts, size simplification and multiple size segregation adaptation for achieving a higher production rate.
{"title":"Design and Development of Size Segregation Sieve Machine with Centrifugal Action","authors":"M. Lee, Pui San Lee","doi":"10.13189/ujme.2020.080406","DOIUrl":"https://doi.org/10.13189/ujme.2020.080406","url":null,"abstract":"This study aims to design and develop a size segregation sieve machine that utilizes centrifugal action to separate impurities from short Oil Palm Frond (OPF) fibers. OPF fibers can manufacture into various products such as erosion control mat and medium density fibreboard as an agricultural waste management program for achieving environmental sustainability. In this aspect, the role of the fiber sieving machine would be significant to support the industry in the production of OPF fibers. However, a thorough literature survey reviewed that limited publications are available in this area; most work done is published in the form of patents. In addition, most fiber sieving machines available in the market utilize manual labour work in the separation phase, where they are highly inefficient. Therefore, this study is designed to fill these gaps. The design of this study adopts the mechanism of various size segregation concepts available and includes centrifugal action in the separation process to increase efficiency. Eventually, a prototype was fabricated for laboratory testing. Several vital parameters are highlighted, which includes mesh surface inclination, sieving duration, a rotation speed of screen and maximum capacity that significantly affects the sieving efficiency. Findings from this study show that sieving duration is less significant to the developed design as higher rotation speed will tend to improve the passing percentage of the fibers. Testing results also revealed the potential application of such a machine in other particle separation applications such as soil separation. For future study, it is recommended to improve the current design in terms of parts, size simplification and multiple size segregation adaptation for achieving a higher production rate.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"860 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130642342","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}
Pub Date : 2020-07-01DOI: 10.13189/ujme.2020.080403
N. Nguyen
In this study, by using Taguchi method, with four controllable factors-three levels (milling type, axial depth of cut, feed rate, and spindle speed), the orthogonal array L27 was used to investigate the effects of milling type and cutting conditions on the surface roughness. By analysis of variance (ANOVA), the influences degree of milling type, axial cutting depth, feed rate, and spindle speed on the surface roughness were 9.26 %, 12.85 %, 12.69 %, and 63.08 %, respectively. The interaction factors of these factors that have a quite small influence on the surface roughness. The surface roughness was modeled as a quadratic regression with the confidence level is more than 99.82%. This model was successfully verified by comparison of experimental and predicted results. The optimization process of surface roughness was performed by both Taguchi method and the ANOVA analysis with the same results. The optimum value of surface roughness was 0.374 µm that was obtained in the half up milling, at a cutting depth of 0.4 mm, a feed rate of 480 mm/min, and a spindle speed of 5000 rpm.
{"title":"A Study on Influence of Milling Types and Cutting Conditions on Surface Roughness in Milling of Aluminum Alloy Al6061-T6","authors":"N. Nguyen","doi":"10.13189/ujme.2020.080403","DOIUrl":"https://doi.org/10.13189/ujme.2020.080403","url":null,"abstract":"In this study, by using Taguchi method, with four controllable factors-three levels (milling type, axial depth of cut, feed rate, and spindle speed), the orthogonal array L27 was used to investigate the effects of milling type and cutting conditions on the surface roughness. By analysis of variance (ANOVA), the influences degree of milling type, axial cutting depth, feed rate, and spindle speed on the surface roughness were 9.26 %, 12.85 %, 12.69 %, and 63.08 %, respectively. The interaction factors of these factors that have a quite small influence on the surface roughness. The surface roughness was modeled as a quadratic regression with the confidence level is more than 99.82%. This model was successfully verified by comparison of experimental and predicted results. The optimization process of surface roughness was performed by both Taguchi method and the ANOVA analysis with the same results. The optimum value of surface roughness was 0.374 µm that was obtained in the half up milling, at a cutting depth of 0.4 mm, a feed rate of 480 mm/min, and a spindle speed of 5000 rpm.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125555530","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}
Pub Date : 2020-07-01DOI: 10.13189/ujme.2020.080409
F. Vidian, Deli Huda Putra
Small-Scale engines are very widely used, especially in developing countries like Indonesia. Its use is intended for various daily activities that require small-scale power. The performance small scale engine is very interesting to investigate for suitable in-field applications. In this study, a small-scale engine was investigated to measure torque (T), brake power (BP), brake mean effective pressure (BMEP) using a rope brake dynamometer with configuration of I. The goal of study is to get an influence of the increase of engine speed on torque, brake power, and BMEP. The experiment was done at engine speed in the range of 1400 to 3500 rpm for each load of 3,4, and 5 kg. The results show an increase in engine speed tends to increase the torque, brake power, and BMEP generated for each load used. The maximum of torque, brake power, and BMEP were 4.53 Nm, 1.67 kW, and 349 kPa respectively at 3521 rpm and the load of 5 kg. The result of brake power of the experiment was compared to report at the literature with differences about 2.3%. The value of BMEP was in the range of standard for small scale engines. This result has given a contribution combined influence of speed and load on the T, BP, and BMEP.
{"title":"An Experimental on Small Scale Gasoline Engine Performance","authors":"F. Vidian, Deli Huda Putra","doi":"10.13189/ujme.2020.080409","DOIUrl":"https://doi.org/10.13189/ujme.2020.080409","url":null,"abstract":"Small-Scale engines are very widely used, especially in developing countries like Indonesia. Its use is intended for various daily activities that require small-scale power. The performance small scale engine is very interesting to investigate for suitable in-field applications. In this study, a small-scale engine was investigated to measure torque (T), brake power (BP), brake mean effective pressure (BMEP) using a rope brake dynamometer with configuration of I. The goal of study is to get an influence of the increase of engine speed on torque, brake power, and BMEP. The experiment was done at engine speed in the range of 1400 to 3500 rpm for each load of 3,4, and 5 kg. The results show an increase in engine speed tends to increase the torque, brake power, and BMEP generated for each load used. The maximum of torque, brake power, and BMEP were 4.53 Nm, 1.67 kW, and 349 kPa respectively at 3521 rpm and the load of 5 kg. The result of brake power of the experiment was compared to report at the literature with differences about 2.3%. The value of BMEP was in the range of standard for small scale engines. This result has given a contribution combined influence of speed and load on the T, BP, and BMEP.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128149440","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}
Pub Date : 2020-07-01DOI: 10.13189/ujme.2020.080407
Abdullah S. Albarqi, A. Boretti
Our world has witnessed a rapid increase in power generation as a result of the growth of population and economy. Currently, people depend on conventional fuel energy as the main source of power generation; however, conventional fuel is well known for its limitation and impact on the environment. Thus, it was necessary to invest in an alternative source of energy such the solar power. Much research and development for solar power such as Concentrated solar power (CSP) have been implemented around the world, and it shows the capability to compete with conventional fuel technology. This paper aims to study the feasibility of constructing 100 MW CSP Linear Fresnel (LF) solar power in Riyadh, Saudi Arabia. In this study, the National Renewable Energy Laboratory (NREL) System Advisor Model (SAM) was used to design, simulate, and analyze the system. The system was designed based on CSP LF technology with molten salt thermal energy storage (TES), where TES supplies the power cycle with the required thermal energy after sunset. The result has revealed the system's capability to produce a good amount of solar power most of the year, reaching up to 38 GWh during summer. The LF system shows a good capacity factor (CF) exceeding 40%. The study shows that Saudi Arabia is a good place to install the CSP LF solar plant.
{"title":"Design of a 100 MW Concentrated Solar Power Linear Fresnel plant with Molten Salt Thermal Energy Storage in Riyadh, Saudi Arabia","authors":"Abdullah S. Albarqi, A. Boretti","doi":"10.13189/ujme.2020.080407","DOIUrl":"https://doi.org/10.13189/ujme.2020.080407","url":null,"abstract":"Our world has witnessed a rapid increase in power generation as a result of the growth of population and economy. Currently, people depend on conventional fuel energy as the main source of power generation; however, conventional fuel is well known for its limitation and impact on the environment. Thus, it was necessary to invest in an alternative source of energy such the solar power. Much research and development for solar power such as Concentrated solar power (CSP) have been implemented around the world, and it shows the capability to compete with conventional fuel technology. This paper aims to study the feasibility of constructing 100 MW CSP Linear Fresnel (LF) solar power in Riyadh, Saudi Arabia. In this study, the National Renewable Energy Laboratory (NREL) System Advisor Model (SAM) was used to design, simulate, and analyze the system. The system was designed based on CSP LF technology with molten salt thermal energy storage (TES), where TES supplies the power cycle with the required thermal energy after sunset. The result has revealed the system's capability to produce a good amount of solar power most of the year, reaching up to 38 GWh during summer. The LF system shows a good capacity factor (CF) exceeding 40%. The study shows that Saudi Arabia is a good place to install the CSP LF solar plant.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128523439","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}
Pub Date : 2020-07-01DOI: 10.13189/ujme.2020.080408
Chukwuneke J. L., Umeji A. C., Sinebe J. E., Fakiyesi O. B.
In this study, investigations were carried out on the energy evaluation, performance analysis and optimization of briquettes produced from biomass wastes (rice-husk and sawdust) and their composites using starch and clay as binders. The proximate compositions of the briquettes were determined following ASTM analytical methods. The moisture content of rice husk and sawdust before briquettes was 20wt.% and 15wt.% respectively. The briquettes produced from bio-waste material of homogeneous particle sizes of 0.5mm and two binders of a percentage of 90:10 which were sun-dried, prepared and moisturized, were reduced to 5wt.% and compressed for the production of briquettes. The energy evaluation of the briquettes was performed using an oxygen bomb calorimeter and the performance test of the briquettes was carried out. Design Expert Central Composite Design Tool was used in the design and Response surface methodology was used to optimize the energy values of rice-husk/sawdust composite briquettes with clay and starch as binders, after which composite briquette made of mahogany sawdust/rice-husk were produced using the optimum condition values of 15% binder starch, 28% rice-husk and 9Mpa compaction pressure. The results showed that composite briquettes of mahogany sawdust and rice-husk produced with starch had a maximum energy value of 5.69kcal/g, while those made with clay had a minimum energy value of 3.35kcal/g. However, the experimental result was less than the predicted optimum value of 2%. This shows that composite briquette made from mahogany sawdust/rice-husk has better energy efficiency than other briquettes considered and it has been observed that starch is a better bonding material than clay. Briquetting technology has great potential to transform waste biomass in affordable, effective and environmentally safe, high-quality solid fuel for households and industry use.
{"title":"Optimization of Composition of Selected Biomass for Briquette Production","authors":"Chukwuneke J. L., Umeji A. C., Sinebe J. E., Fakiyesi O. B.","doi":"10.13189/ujme.2020.080408","DOIUrl":"https://doi.org/10.13189/ujme.2020.080408","url":null,"abstract":"In this study, investigations were carried out on the energy evaluation, performance analysis and optimization of briquettes produced from biomass wastes (rice-husk and sawdust) and their composites using starch and clay as binders. The proximate compositions of the briquettes were determined following ASTM analytical methods. The moisture content of rice husk and sawdust before briquettes was 20wt.% and 15wt.% respectively. The briquettes produced from bio-waste material of homogeneous particle sizes of 0.5mm and two binders of a percentage of 90:10 which were sun-dried, prepared and moisturized, were reduced to 5wt.% and compressed for the production of briquettes. The energy evaluation of the briquettes was performed using an oxygen bomb calorimeter and the performance test of the briquettes was carried out. Design Expert Central Composite Design Tool was used in the design and Response surface methodology was used to optimize the energy values of rice-husk/sawdust composite briquettes with clay and starch as binders, after which composite briquette made of mahogany sawdust/rice-husk were produced using the optimum condition values of 15% binder starch, 28% rice-husk and 9Mpa compaction pressure. The results showed that composite briquettes of mahogany sawdust and rice-husk produced with starch had a maximum energy value of 5.69kcal/g, while those made with clay had a minimum energy value of 3.35kcal/g. However, the experimental result was less than the predicted optimum value of 2%. This shows that composite briquette made from mahogany sawdust/rice-husk has better energy efficiency than other briquettes considered and it has been observed that starch is a better bonding material than clay. Briquetting technology has great potential to transform waste biomass in affordable, effective and environmentally safe, high-quality solid fuel for households and industry use.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125920471","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}
Pub Date : 2020-07-01DOI: 10.13189/ujme.2020.080405
R. S. Ibramsa, M. J. A. Latif, M. S. Zakaria, M. N. Harun, J. Mahmud
Degeneration and loss of articular cartilage in the synovial joint have been recognized as the main source of osteoarthritis which leads to pain, swelling and limit the joint mobility. Extensive experimental and computational studies have been performed to study the mechanical behavior and characterize the biomechanical properties of articular cartilage. However, a lack of attention was made on the curvature of the cartilage surface by assuming it was a flat surface. This assumption was inappropriate since the synovial joints possessed curved geometrical shape and may contribute to inaccuracies in characterizing the articular cartilage biomechanical properties. This study aims to examine the effects of the curvature of the cartilage surface in finite element modeling which incorporated with the experiment method to characterize biomechanical properties of articular cartilage. In this study, the biomechanical behavior of contact pressure and pore pressure were investigated at different radius of cartilage surface using the finite element method. The cartilage biomechanical properties of elastic modulus and permeability of the bovine humeral head were then characterized using a combination of indentation test and finite element method. It was found that the cartilage curvature produced a 6% difference in contact pressure and a 39% difference in pore pressure distribution compared to the flat surface cartilage in finite element analysis. Furthermore, significant observation in the characterized biomechanical properties was obtained where the differences of the cartilage curvature reached 33% for elastic modulus and 56% for permeability. Based on the results, the surface curvature of articular cartilage could play an important role in the computational modeling and characterization of its biomechanical properties.
{"title":"Finite Element Modeling of Articular Cartilage to Characterize Biomechanical Properties: The Effect of Cartilage Surface Curvature","authors":"R. S. Ibramsa, M. J. A. Latif, M. S. Zakaria, M. N. Harun, J. Mahmud","doi":"10.13189/ujme.2020.080405","DOIUrl":"https://doi.org/10.13189/ujme.2020.080405","url":null,"abstract":"Degeneration and loss of articular cartilage in the synovial joint have been recognized as the main source of osteoarthritis which leads to pain, swelling and limit the joint mobility. Extensive experimental and computational studies have been performed to study the mechanical behavior and characterize the biomechanical properties of articular cartilage. However, a lack of attention was made on the curvature of the cartilage surface by assuming it was a flat surface. This assumption was inappropriate since the synovial joints possessed curved geometrical shape and may contribute to inaccuracies in characterizing the articular cartilage biomechanical properties. This study aims to examine the effects of the curvature of the cartilage surface in finite element modeling which incorporated with the experiment method to characterize biomechanical properties of articular cartilage. In this study, the biomechanical behavior of contact pressure and pore pressure were investigated at different radius of cartilage surface using the finite element method. The cartilage biomechanical properties of elastic modulus and permeability of the bovine humeral head were then characterized using a combination of indentation test and finite element method. It was found that the cartilage curvature produced a 6% difference in contact pressure and a 39% difference in pore pressure distribution compared to the flat surface cartilage in finite element analysis. Furthermore, significant observation in the characterized biomechanical properties was obtained where the differences of the cartilage curvature reached 33% for elastic modulus and 56% for permeability. Based on the results, the surface curvature of articular cartilage could play an important role in the computational modeling and characterization of its biomechanical properties.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131346834","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}
Pub Date : 2020-07-01DOI: 10.13189/ujme.2020.080402
A. Zenani, T. Dzogbewu, W. D. Preez, I. Yadroitsev
Titanium aluminides have become the preferred titanium-based alloys for high temperature applications due to their resistance to oxidation at elevated temperatures. However, the inherent limitations of the conventional methods of manufacturing have adverse effects on the mechanical properties of the alloy and limit its applications. The current study focused on determining the optimum process parameters that could be used to produce a Ti6Al alloy with required microstructural properties and complex geometrical configurations using the direct metal laser sintering method. Single tracks were produced at laser powers of 150 W and 350 W over a wide range of scanning speeds. Continuous tracks were achieved only at a laser power of 150 W at corresponding scanning speeds of 1.0 m/s to 1.4 m/s. A cross sectional analysis was conducted on the single tracks and 1.2 m/s emerged as the optimum scanning speed. 3D objects were manufactured at optimum process parameters of 150 W, 1.2 m/s and a hatch distance of 80 µm. The microstructure of the 3D objects was homogenous which attests that the direct metal laser sintering method could be used to produce Ti6Al parts with the desired mechanical properties and geometrical complexity.
钛铝化物因其在高温下的抗氧化性而成为高温应用的首选钛基合金。然而，传统制造方法的固有局限性对合金的机械性能产生不利影响，限制了其应用。目前的研究重点是确定最佳工艺参数，该参数可用于使用直接金属激光烧结方法生产具有所需显微组织性能和复杂几何构型的Ti6Al合金。单磁道的激光功率为150瓦和350瓦，扫描速度范围很宽。激光功率为150 W，扫描速度为1.0 m/s ~ 1.4 m/s，实现了连续轨迹。对单轨进行横断面分析，发现最佳扫描速度为1.2 m/s。在最佳工艺参数为150 W、1.2 m/s、80µm的条件下制备三维物体。三维物体的微观结构均匀，证明了直接金属激光烧结方法可以生产出具有理想力学性能和几何复杂度的Ti6Al零件。
{"title":"Optimum Process Parameters for Direct Metal Laser Sintering of Ti6Al Powder Blend","authors":"A. Zenani, T. Dzogbewu, W. D. Preez, I. Yadroitsev","doi":"10.13189/ujme.2020.080402","DOIUrl":"https://doi.org/10.13189/ujme.2020.080402","url":null,"abstract":"Titanium aluminides have become the preferred titanium-based alloys for high temperature applications due to their resistance to oxidation at elevated temperatures. However, the inherent limitations of the conventional methods of manufacturing have adverse effects on the mechanical properties of the alloy and limit its applications. The current study focused on determining the optimum process parameters that could be used to produce a Ti6Al alloy with required microstructural properties and complex geometrical configurations using the direct metal laser sintering method. Single tracks were produced at laser powers of 150 W and 350 W over a wide range of scanning speeds. Continuous tracks were achieved only at a laser power of 150 W at corresponding scanning speeds of 1.0 m/s to 1.4 m/s. A cross sectional analysis was conducted on the single tracks and 1.2 m/s emerged as the optimum scanning speed. 3D objects were manufactured at optimum process parameters of 150 W, 1.2 m/s and a hatch distance of 80 µm. The microstructure of the 3D objects was homogenous which attests that the direct metal laser sintering method could be used to produce Ti6Al parts with the desired mechanical properties and geometrical complexity.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"62 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125937687","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}
Pub Date : 2020-05-01DOI: 10.13189/ujme.2020.080303
Atif Alkhazali, Akram Alsukker, Morad Etier, M. Hamasha
The dielectric permittivity and conductivity of (AgPO3)1-x(Ag2SO4)x compound was investigated at different concentrations of (Ag2SO4). The effect of concentration on AC conductivity and permittivity as well as temperature and frequency was investigated in order to model this behavior. Multidimensional mathematical models were as proposed to predict the impedance components and the dielectric permittivity components of the glass system as a function of temperatures, frequencies and concentrations. Artificial Neural Network (ANN) and nonlinear regression approaches were set as curve fitting techniques in order to construct models based on 1700 points of data. This model can be then used to predict these proprieties at any concentration and therefore helping the product designer to choose the proper mixing and temperature conditions. For ANN, 20, 50, and 100 nodes in a single hidden layer neural network were considered. Although data results of the two approaches showed a good alignment with experimental data, the ANN model with twenty nodes was able to predict the outputs with lower MSE values range from 0.008 to 0.012 for impedance and from 0.006 to 0.008 for dielectric losses than the regression technique. Moreover, R2 values for the neural network were over 99% in both training and testing of impedance and dielectric permittivity while R2 values for non-linear regression vary between 73.86% to 94.75%. The proposed ANN model can be of a great help to find the optimal dielectric permittivity and conductivity of (AgPO3)1-x(Ag2SO4)x compound when dealing with a specific application.
{"title":"Modeling the Impedance Behavior of Ionic Conductors (AgPO3)1-x(Ag2SO4)x Glass System Using Artificial Neural Network","authors":"Atif Alkhazali, Akram Alsukker, Morad Etier, M. Hamasha","doi":"10.13189/ujme.2020.080303","DOIUrl":"https://doi.org/10.13189/ujme.2020.080303","url":null,"abstract":"The dielectric permittivity and conductivity of (AgPO3)1-x(Ag2SO4)x compound was investigated at different concentrations of (Ag2SO4). The effect of concentration on AC conductivity and permittivity as well as temperature and frequency was investigated in order to model this behavior. Multidimensional mathematical models were as proposed to predict the impedance components and the dielectric permittivity components of the glass system as a function of temperatures, frequencies and concentrations. Artificial Neural Network (ANN) and nonlinear regression approaches were set as curve fitting techniques in order to construct models based on 1700 points of data. This model can be then used to predict these proprieties at any concentration and therefore helping the product designer to choose the proper mixing and temperature conditions. For ANN, 20, 50, and 100 nodes in a single hidden layer neural network were considered. Although data results of the two approaches showed a good alignment with experimental data, the ANN model with twenty nodes was able to predict the outputs with lower MSE values range from 0.008 to 0.012 for impedance and from 0.006 to 0.008 for dielectric losses than the regression technique. Moreover, R2 values for the neural network were over 99% in both training and testing of impedance and dielectric permittivity while R2 values for non-linear regression vary between 73.86% to 94.75%. The proposed ANN model can be of a great help to find the optimal dielectric permittivity and conductivity of (AgPO3)1-x(Ag2SO4)x compound when dealing with a specific application.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127494265","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}
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