Pub Date : 2023-06-28DOI: 10.15282/jmes.17.2.2023.5.0749
A. Pingale, Pravin S. Kachare
Over the past few decades, research on impact dampers has grown significantly, leading to numerous analytical and experimental investigations in that field. Vibrations can harm industrial equipment and cause process errors. Particle impact damper has a significant impact on lowering vibration and has been broadly implemented in various engineering applications. This work deals with the theoretical modeling for cantilever beam and fixed-fixed beam attached with a cylindrical enclosure filled with particles. Transient and forced excitations are considered to trace the motion of the primary mass with respect to time. Also, theoretical modeling of particle arrangement in enclosure, condition for particles to detach from base or ceiling of enclosure, motion of particle after detachment from enclosure, and mechanism of collision and friction of particles are discussed and presented in detail. Theoretical models proposed in this study can be used to generate theoretical readings for practical engineering applications.
{"title":"Establishment of theoretical models for beam structures with particle impact damper","authors":"A. Pingale, Pravin S. Kachare","doi":"10.15282/jmes.17.2.2023.5.0749","DOIUrl":"https://doi.org/10.15282/jmes.17.2.2023.5.0749","url":null,"abstract":"Over the past few decades, research on impact dampers has grown significantly, leading to numerous analytical and experimental investigations in that field. Vibrations can harm industrial equipment and cause process errors. Particle impact damper has a significant impact on lowering vibration and has been broadly implemented in various engineering applications. This work deals with the theoretical modeling for cantilever beam and fixed-fixed beam attached with a cylindrical enclosure filled with particles. Transient and forced excitations are considered to trace the motion of the primary mass with respect to time. Also, theoretical modeling of particle arrangement in enclosure, condition for particles to detach from base or ceiling of enclosure, motion of particle after detachment from enclosure, and mechanism of collision and friction of particles are discussed and presented in detail. Theoretical models proposed in this study can be used to generate theoretical readings for practical engineering applications.","PeriodicalId":16166,"journal":{"name":"Journal of Mechanical Engineering and Sciences","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48494216","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 : 2023-06-28DOI: 10.15282/jmes.17.2.2023.3.0747
Ahmad Syafiq Haqim, W. W. Wan Mohamed, Al Hassan Salami Tijjani
Steam is essential in petrochemical industries for the transportation of thermal energy and usage in some reforming process. Superheaters are heat exchangers that convert saturated steam to dry steam by utilizing waste heat from the flue gas stream. Medium pressure steam superheaters are prone to tube deterioration due to service at elevated temperatures and erosion from the presence of liquid phase in the steam, leading to tube plugging after tube failure. This reduces the overall surface heating area of the superheater. Relations between the tube plugging practice and the energy dynamics of the superheaters are important for engineers to identify the responses of the superheater for operation planning, and this issue has not been extensively explored academically. This article analyses the deterioration of superheater performance due to reduction of surface heating area based on operational data of a petrochemical steam generation line. The objective is to find relations between the effect of tube plugging on the states of both steam and flue gas streams, as well as its impact on the overall energy exchange. The operating conditions of a superheater at two separate service years, before (year 2014) and after (year 2017) tube plugging, were compared through the first law energy analysis. The average steam inlet temperatures were between 248 °C and 250 °C, at flow rates between 70 and 90 ton/hour. The analysis indicated that 0.3 to 0.8 % increase in inlet energy is required for every plugged tube to compensate for the reduction of heating surface. At 3 % reduction of heating surface area, the heat exchanger effectiveness decreases by an average of 11 % that also leads to a lower steam temperature output by approximately 6% from the design operating temperature. These results would assist steam engineers to analyse changes to the energy economics of the whole plant and decide the feasibility of replacing existing superheaters with new ones. Also, another significant finding to be considered by steam engineers is that the current practice of increasing the steam flow rate does not offset the loss of energy effectiveness due to tube plugging.
{"title":"Performance degradation analysis of a medium pressure superheater due to tube deactivation","authors":"Ahmad Syafiq Haqim, W. W. Wan Mohamed, Al Hassan Salami Tijjani","doi":"10.15282/jmes.17.2.2023.3.0747","DOIUrl":"https://doi.org/10.15282/jmes.17.2.2023.3.0747","url":null,"abstract":"Steam is essential in petrochemical industries for the transportation of thermal energy and usage in some reforming process. Superheaters are heat exchangers that convert saturated steam to dry steam by utilizing waste heat from the flue gas stream. Medium pressure steam superheaters are prone to tube deterioration due to service at elevated temperatures and erosion from the presence of liquid phase in the steam, leading to tube plugging after tube failure. This reduces the overall surface heating area of the superheater. Relations between the tube plugging practice and the energy dynamics of the superheaters are important for engineers to identify the responses of the superheater for operation planning, and this issue has not been extensively explored academically. This article analyses the deterioration of superheater performance due to reduction of surface heating area based on operational data of a petrochemical steam generation line. The objective is to find relations between the effect of tube plugging on the states of both steam and flue gas streams, as well as its impact on the overall energy exchange. The operating conditions of a superheater at two separate service years, before (year 2014) and after (year 2017) tube plugging, were compared through the first law energy analysis. The average steam inlet temperatures were between 248 °C and 250 °C, at flow rates between 70 and 90 ton/hour. The analysis indicated that 0.3 to 0.8 % increase in inlet energy is required for every plugged tube to compensate for the reduction of heating surface. At 3 % reduction of heating surface area, the heat exchanger effectiveness decreases by an average of 11 % that also leads to a lower steam temperature output by approximately 6% from the design operating temperature. These results would assist steam engineers to analyse changes to the energy economics of the whole plant and decide the feasibility of replacing existing superheaters with new ones. Also, another significant finding to be considered by steam engineers is that the current practice of increasing the steam flow rate does not offset the loss of energy effectiveness due to tube plugging.","PeriodicalId":16166,"journal":{"name":"Journal of Mechanical Engineering and Sciences","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47786480","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 : 2023-06-28DOI: 10.15282/jmes.17.2.2023.7.0751
I. Mat Sahat, M. R. Mat Rejab, Quanjin Ma
In this research, the use of three-dimensional (3D) printing among Malaysian users was studied. The aim of the research is to establish the demographics and use of 3D printing in Malaysia. A questionnaire was distributed among 3D printing users during a 3D printing webinar and via social media groups consisting of 3D printer users. For the demographic section, 74 males and 8 females responded to the questionnaire, with more than 90% of the respondents have tertiary education. 39% of the respondents are from Greater Klang Valley, and 33% of the respondents are self-employed. The highest application of 3D printing is for hobby (i.e., 67% of the respondents), while the highest response for experience in 3D printing is 28% with 1–3 years of experience. Creality 3D printer brand is the most selected printer brand, with 64.7% of the respondents using the brand. 33% of the respondents used the printer at a heavy usage rate of 5 days per week, which is the highest response. For the material used, 85.4% of the respondents agreed that they normally used polylactic acid, while 79.3% of the respondents selected Cura as the most used software. Furthermore, 79.3% of the respondents stated that the infill percentage setting as the most changed setting, while 63.4% of the respondents agreed that bed levelling is the most common problem in 3D printing. In the opinion section, most of the respondents believed that 3D printing technology is still new and should be taught in schools. Based on the results, the research has successfully established the demographics and usage among 3D printer users in Malaysia.
{"title":"A study on 3D printing usage among Malaysian users","authors":"I. Mat Sahat, M. R. Mat Rejab, Quanjin Ma","doi":"10.15282/jmes.17.2.2023.7.0751","DOIUrl":"https://doi.org/10.15282/jmes.17.2.2023.7.0751","url":null,"abstract":"In this research, the use of three-dimensional (3D) printing among Malaysian users was studied. The aim of the research is to establish the demographics and use of 3D printing in Malaysia. A questionnaire was distributed among 3D printing users during a 3D printing webinar and via social media groups consisting of 3D printer users. For the demographic section, 74 males and 8 females responded to the questionnaire, with more than 90% of the respondents have tertiary education. 39% of the respondents are from Greater Klang Valley, and 33% of the respondents are self-employed. The highest application of 3D printing is for hobby (i.e., 67% of the respondents), while the highest response for experience in 3D printing is 28% with 1–3 years of experience. Creality 3D printer brand is the most selected printer brand, with 64.7% of the respondents using the brand. 33% of the respondents used the printer at a heavy usage rate of 5 days per week, which is the highest response. For the material used, 85.4% of the respondents agreed that they normally used polylactic acid, while 79.3% of the respondents selected Cura as the most used software. Furthermore, 79.3% of the respondents stated that the infill percentage setting as the most changed setting, while 63.4% of the respondents agreed that bed levelling is the most common problem in 3D printing. In the opinion section, most of the respondents believed that 3D printing technology is still new and should be taught in schools. Based on the results, the research has successfully established the demographics and usage among 3D printer users in Malaysia.","PeriodicalId":16166,"journal":{"name":"Journal of Mechanical Engineering and Sciences","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46393157","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 : 2023-06-28DOI: 10.15282/jmes.17.2.2023.10.0754
Jun Hong Cheok, Kah Onn Lee, V. R. Aparow, N.H. Amer, C.S.P. Peter, K. Magaswaran
Autonomous vehicle (AV) requires millions of miles on road to test the reliability of safety systems. It is also difficult to test the AV for critical scenarios which are rare but will endanger road users. Therefore, virtual safety testing simulation platforms are introduced to test the safety systems of the autonomous vehicles in critical scenarios. However, developing the virtual safety testing simulation platform requires information about the environment and driving data from the real world. Besides, it is challenging to build a system to collect driving data which is normally cost intensive especially in developing countries. Paradoxically, these developing countries have poor traffic environment which can provide valuable scenarios for safety testing test cases. Therefore, in this paper, a scenario-based testing using virtual simulation platform is developed using data captured by a low-cost sensor-based instrumented vehicle. The instrumented vehicle is built by low-cost off-the-shelf components for the testing purpose. The instrumented vehicle is used for validation process in IPG CarMaker’s vehicle model using SAE standards. Then, the validated vehicle model is used as an autonomous vehicle in IPG CarMaker for the virtual scenario-based safety testing. The whole validation process from data collection to data logging is carried out using various economic sensors instead of a single industrial system. This approach greatly reduce the cost of the instrumented vehicle and the result of the scenario-based testing shows that the virtual scenarios developed in IPG CarMaker can be used for validation purpose with actual scenarios using low-cost sensor based instrumented vehicle as low as 4% root mean square percentage error.
{"title":"Validation of scenario-based virtual safety testing using low-cost sensor-based instrumented vehicle","authors":"Jun Hong Cheok, Kah Onn Lee, V. R. Aparow, N.H. Amer, C.S.P. Peter, K. Magaswaran","doi":"10.15282/jmes.17.2.2023.10.0754","DOIUrl":"https://doi.org/10.15282/jmes.17.2.2023.10.0754","url":null,"abstract":"Autonomous vehicle (AV) requires millions of miles on road to test the reliability of safety systems. It is also difficult to test the AV for critical scenarios which are rare but will endanger road users. Therefore, virtual safety testing simulation platforms are introduced to test the safety systems of the autonomous vehicles in critical scenarios. However, developing the virtual safety testing simulation platform requires information about the environment and driving data from the real world. Besides, it is challenging to build a system to collect driving data which is normally cost intensive especially in developing countries. Paradoxically, these developing countries have poor traffic environment which can provide valuable scenarios for safety testing test cases. Therefore, in this paper, a scenario-based testing using virtual simulation platform is developed using data captured by a low-cost sensor-based instrumented vehicle. The instrumented vehicle is built by low-cost off-the-shelf components for the testing purpose. The instrumented vehicle is used for validation process in IPG CarMaker’s vehicle model using SAE standards. Then, the validated vehicle model is used as an autonomous vehicle in IPG CarMaker for the virtual scenario-based safety testing. The whole validation process from data collection to data logging is carried out using various economic sensors instead of a single industrial system. This approach greatly reduce the cost of the instrumented vehicle and the result of the scenario-based testing shows that the virtual scenarios developed in IPG CarMaker can be used for validation purpose with actual scenarios using low-cost sensor based instrumented vehicle as low as 4% root mean square percentage error.","PeriodicalId":16166,"journal":{"name":"Journal of Mechanical Engineering and Sciences","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48801874","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 : 2023-06-28DOI: 10.15282/jmes.17.2.2023.8.0752
Fethi Khelfaoui, M. A. Yallese, N. Ouelaa, S. Chihaoui, S. Belhadi
Intermittent machining is characterized by its complex and irregular context. This intermittency causes machining to occur under difficult conditions that greatly influence the technological performance parameters. The aim of the present work is to evaluate the effects of input parameters, cutting speed, Vc, depth of cut, ap, tool nose radius, r and feed rate, f, on surface roughness, Ra, tangential cutting force, Fz, motor power consumption, Pm, cutting power, Pc and material removal rate (MRR), during intermittent turning (IT) of AISI D3 tool steel. Machining was performed with a triple CVD coated carbide tool (AI2O3/TiC/TiCN) by adopting a Taguchi L9 (3^4) experimental design. The ANOVA and RSM methods were used to analyze the effects of cutting factors on the outputs parameters resulting in statistical prediction models. In addition, a multi-objective optimization of the cutting conditions exploiting the desirability function (DF) was done according to four cases of relative importance corresponding to different industrial contexts. Furthermore, the grey relational analysis (GRA) method was applied and compared with the DF method. The results show that the optimal regime found by the DF method, (r =1.6mm, Vc= 240 m/min, f = 0.084 mm/rev and ap = 0.64 mm), favors Ra and MRR. On the other hand, for the GRA method, the combination of (r = 0.4 mm, Vc = 240 m/min f = 0.08 mm/rev and ap = 0.3 mm) favors the minimization of Fz, Pm and Pc. This work presents an originality because the results found are very useful in the field of optimization for a better control of the process IT.
{"title":"Statistical analysis, modeling and multi-objective optimization of parameters intermittent turning process of AISI D3","authors":"Fethi Khelfaoui, M. A. Yallese, N. Ouelaa, S. Chihaoui, S. Belhadi","doi":"10.15282/jmes.17.2.2023.8.0752","DOIUrl":"https://doi.org/10.15282/jmes.17.2.2023.8.0752","url":null,"abstract":"Intermittent machining is characterized by its complex and irregular context. This intermittency causes machining to occur under difficult conditions that greatly influence the technological performance parameters. The aim of the present work is to evaluate the effects of input parameters, cutting speed, Vc, depth of cut, ap, tool nose radius, r and feed rate, f, on surface roughness, Ra, tangential cutting force, Fz, motor power consumption, Pm, cutting power, Pc and material removal rate (MRR), during intermittent turning (IT) of AISI D3 tool steel. Machining was performed with a triple CVD coated carbide tool (AI2O3/TiC/TiCN) by adopting a Taguchi L9 (3^4) experimental design. The ANOVA and RSM methods were used to analyze the effects of cutting factors on the outputs parameters resulting in statistical prediction models. In addition, a multi-objective optimization of the cutting conditions exploiting the desirability function (DF) was done according to four cases of relative importance corresponding to different industrial contexts. Furthermore, the grey relational analysis (GRA) method was applied and compared with the DF method. The results show that the optimal regime found by the DF method, (r =1.6mm, Vc= 240 m/min, f = 0.084 mm/rev and ap = 0.64 mm), favors Ra and MRR. On the other hand, for the GRA method, the combination of (r = 0.4 mm, Vc = 240 m/min f = 0.08 mm/rev and ap = 0.3 mm) favors the minimization of Fz, Pm and Pc. This work presents an originality because the results found are very useful in the field of optimization for a better control of the process IT.","PeriodicalId":16166,"journal":{"name":"Journal of Mechanical Engineering and Sciences","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49624243","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 : 2023-06-15DOI: 10.15282/jmes.13.4.2019.10.0466
B. Arifvianto, A. Putra, B. T. Prayoga, R. Dharmastiti, U. A. Salim, M. Mahardika, Suyitno .
Fused deposition modelling (FDM) has so far been recognized for its reliability and simplicity for manufacturing of geometrically-complex polymeric materials with 3D printing technique. Recently, the studies concerning the properties of materials fabricated by using the FDM have been growing, including those related to their wear resistance which is considered of critical when a 3D-printed material must work sliding over the surface of another material during its application. Up to now, however, the influence of several FDM-printing parameters, including the raster orientations, on the wear resistance of the printed polymeric materials have not yet been fully understood. In this research, the influence of raster orientations on the wear resistance of FDM-processed polylactic-acid (PLA) materials in bovine blood serum were determined. A reciprocating pin-on-plate tribometer was used to evaluate wear resistance of a cylindrical PLA pin that slid over the surface of a commercially-pure titanium (Ti) plate. The results showed that the FDM-printed PLA pins with unidirectional raster orientations had higher wear factors (WF), i.e., ~1.5 ´ 10-4 mm N-1 m-1 than those with crossed raster orientations, i.e., ~0.8 ´ 10-4 mm N-1 m-1. Meanwhile, the WF values of Ti surface that slid against PLA pin with crossed raster orientations, i.e., ~0.09 ´ 10-4 mm N-1 m-1, were also significantly lower than those sliding with the pin having unidirectional raster orientation, i.e., 0.34 – 0.41 ´ 10-4 mm N-1 m-1. The result of analysis of the worn surface morphologies shows the indications of surface abrasion, fatigue and polymer film transfer as the possible wear mechanisms of both the FDM-processed PLA pin and its Ti countersurface material. On the basis of all the findings in this research, it can be concluded that the crossed raster orientation is preferable to be used as one of the parameters in printing of the wear resistant PLA rather than the unidirectional raster orientation.
迄今为止，熔融沉积建模(FDM)以其可靠性和简单性为3D打印技术制造几何复杂聚合物材料的公认。最近，关于使用FDM制造的材料性能的研究越来越多，其中包括与耐磨性相关的研究，当3d打印材料在应用过程中必须在另一种材料的表面滑动时，耐磨性被认为是至关重要的。然而，到目前为止，包括光栅取向在内的几个fdm打印参数对打印聚合物材料耐磨性的影响尚未完全了解。本研究测定了光栅取向对fdm加工的聚乳酸(PLA)材料在牛血清中耐磨性的影响。使用往复式销板摩擦计来评估在商业纯钛(Ti)板表面滑动的圆柱形PLA销的耐磨性。结果表明，单向光栅取向的fdm打印PLA引脚的磨损因子WF(~1.5´10-4 mm N-1 m-1)高于交叉光栅取向的WF(~0.8´10-4 mm N-1 m-1)。与此同时，Ti表面与具有交叉栅格取向的PLA销滑动时的WF值(~0.09´10-4 mm N-1 m-1)也显著低于与具有单向栅格取向的PLA销滑动时的WF值(0.34 ~ 0.41´10-4 mm N-1 m-1)。磨损表面形貌分析结果表明，表面磨损、疲劳和聚合物膜转移是fdm加工PLA销及其Ti反表面材料的可能磨损机制。综合以上研究结果，可以得出交叉栅格取向比单向栅格取向更适合作为耐磨聚乳酸打印的参数之一。
{"title":"Sliding wear characteristics of FDM-processed polylactic-acid in bovine blood serum","authors":"B. Arifvianto, A. Putra, B. T. Prayoga, R. Dharmastiti, U. A. Salim, M. Mahardika, Suyitno .","doi":"10.15282/jmes.13.4.2019.10.0466","DOIUrl":"https://doi.org/10.15282/jmes.13.4.2019.10.0466","url":null,"abstract":"Fused deposition modelling (FDM) has so far been recognized for its reliability and simplicity for manufacturing of geometrically-complex polymeric materials with 3D printing technique. Recently, the studies concerning the properties of materials fabricated by using the FDM have been growing, including those related to their wear resistance which is considered of critical when a 3D-printed material must work sliding over the surface of another material during its application. Up to now, however, the influence of several FDM-printing parameters, including the raster orientations, on the wear resistance of the printed polymeric materials have not yet been fully understood. In this research, the influence of raster orientations on the wear resistance of FDM-processed polylactic-acid (PLA) materials in bovine blood serum were determined. A reciprocating pin-on-plate tribometer was used to evaluate wear resistance of a cylindrical PLA pin that slid over the surface of a commercially-pure titanium (Ti) plate. The results showed that the FDM-printed PLA pins with unidirectional raster orientations had higher wear factors (WF), i.e., ~1.5 ´ 10-4 mm N-1 m-1 than those with crossed raster orientations, i.e., ~0.8 ´ 10-4 mm N-1 m-1. Meanwhile, the WF values of Ti surface that slid against PLA pin with crossed raster orientations, i.e., ~0.09 ´ 10-4 mm N-1 m-1, were also significantly lower than those sliding with the pin having unidirectional raster orientation, i.e., 0.34 – 0.41 ´ 10-4 mm N-1 m-1. The result of analysis of the worn surface morphologies shows the indications of surface abrasion, fatigue and polymer film transfer as the possible wear mechanisms of both the FDM-processed PLA pin and its Ti countersurface material. On the basis of all the findings in this research, it can be concluded that the crossed raster orientation is preferable to be used as one of the parameters in printing of the wear resistant PLA rather than the unidirectional raster orientation.","PeriodicalId":16166,"journal":{"name":"Journal of Mechanical Engineering and Sciences","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47319190","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 : 2023-05-24DOI: 10.15282/jmes.15.3.2021.10.0654
Muhammad Penta Helios, Wanchai Asvapoositkul
This paper presented an implementation of entropy generation analysis in the main flow field of a water jet pump via the CFD method. This study aimed to identify the inefficient location of energy conversion and to analyse entropy generation sources in each region of the water jet pump. The 2D-axisymmetric model and realisable k-ε (RKE) turbulence model at steady-state conditions were performed to validate jet pump performance and to assess the entropy generation. Likewise, the effects of the projection ratio and throat-aspect ratio as independent parameters were investigated. As a result, the throat is the most inefficient part due to the high total entropy generation rate, following by diffuser part. Also, the entropy generation rate was assessed dominant than viscous dissipation due to the turbulent dissipation, which was caused by a turbulent shear stress layer of mixing the streams. In conclusion, the projection ratio influenced the growth of the shear stress layer as well as the entropy generation. Further, the throat-aspect ratio affected the distribution of entropy generation in the throat section. An appropriate combination of both parameters has an impact on the jet pump performance improvements reducing the entropy generation rate in the future.
{"title":"Numerical studies for effect of geometrical parameters on water jet pump performance via entropy generation analysis","authors":"Muhammad Penta Helios, Wanchai Asvapoositkul","doi":"10.15282/jmes.15.3.2021.10.0654","DOIUrl":"https://doi.org/10.15282/jmes.15.3.2021.10.0654","url":null,"abstract":"This paper presented an implementation of entropy generation analysis in the main flow field of a water jet pump via the CFD method. This study aimed to identify the inefficient location of energy conversion and to analyse entropy generation sources in each region of the water jet pump. The 2D-axisymmetric model and realisable k-ε (RKE) turbulence model at steady-state conditions were performed to validate jet pump performance and to assess the entropy generation. Likewise, the effects of the projection ratio and throat-aspect ratio as independent parameters were investigated. As a result, the throat is the most inefficient part due to the high total entropy generation rate, following by diffuser part. Also, the entropy generation rate was assessed dominant than viscous dissipation due to the turbulent dissipation, which was caused by a turbulent shear stress layer of mixing the streams. In conclusion, the projection ratio influenced the growth of the shear stress layer as well as the entropy generation. Further, the throat-aspect ratio affected the distribution of entropy generation in the throat section. An appropriate combination of both parameters has an impact on the jet pump performance improvements reducing the entropy generation rate in the future.","PeriodicalId":16166,"journal":{"name":"Journal of Mechanical Engineering and Sciences","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135090542","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 : 2023-04-15DOI: 10.24191/jmeche.v20i2.22050
Vivien S. Djanali
The new Contra-rotating Darrieus turbine configuration has been invented to enhance the V ertical Axis Wind Turbine (VAWT) performance. This configuration increases the relative rotational speed of the generator, resulting in higher output power. It is well known that the increase can reach four times the output power. However, how the Darrieus turbine VAWT contra- rotating configuration influences its aerodynamic performance still needs to be discovered. This study investigates the aerodynamic performance of the contra-rotating configuration by comparing it to the single-rotating Darrieus turbine VAWT under the same conditions. The freestream speed is 5 m/s, with TSR varying from one to two intervals of 0.2. This research is being completed using Computational Fluid Dynamics (CFD) 3D cases with an Unsteady Reynold Average Navier-Stokes (URANS) equation as the turbulent model equation. The results of this study show that in terms of output power or Power coefficient (Cp), the contra-rotating has a greater value than the single- rotating configuration. However, in all TSR variations, contra-rotating outperforms single-rotating in terms of aerodynamic performance or moment coefficient (Cm). This is due to the fact that the aspect ratio of stage 1 contra-rotating rotor is lower than the single-rotating rotor, resulting in more significant blade tip losses in contra-rotating. Theflow was discovered through the gap between stages 1 and 2 contra-rotating, providing additional momentum. This phenomenon increases Cm at an azimuth angle of 200°-255°.
{"title":"Numerical Study of Contra-Rotating Vertical Axis Wind Turbine H-Rotor Darrieus Type","authors":"Vivien S. Djanali","doi":"10.24191/jmeche.v20i2.22050","DOIUrl":"https://doi.org/10.24191/jmeche.v20i2.22050","url":null,"abstract":"The new Contra-rotating Darrieus turbine configuration has been invented to enhance the V ertical Axis Wind Turbine (VAWT) performance. This configuration increases the relative rotational speed of the generator, resulting in higher output power. It is well known that the increase can reach four times the output power. However, how the Darrieus turbine VAWT contra- rotating configuration influences its aerodynamic performance still needs to be discovered. This study investigates the aerodynamic performance of the contra-rotating configuration by comparing it to the single-rotating Darrieus turbine VAWT under the same conditions. The freestream speed is 5 m/s, with TSR varying from one to two intervals of 0.2. This research is being completed using Computational Fluid Dynamics (CFD) 3D cases with an Unsteady Reynold Average Navier-Stokes (URANS) equation as the turbulent model equation. The results of this study show that in terms of output power or Power coefficient (Cp), the contra-rotating has a greater value than the single- rotating configuration. However, in all TSR variations, contra-rotating outperforms single-rotating in terms of aerodynamic performance or moment coefficient (Cm). This is due to the fact that the aspect ratio of stage 1 contra-rotating rotor is lower than the single-rotating rotor, resulting in more significant blade tip losses in contra-rotating. Theflow was discovered through the gap between stages 1 and 2 contra-rotating, providing additional momentum. This phenomenon increases Cm at an azimuth angle of 200°-255°.","PeriodicalId":16166,"journal":{"name":"Journal of Mechanical Engineering and Sciences","volume":"167 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75797104","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 : 2023-04-15DOI: 10.24191/jmeche.v20i2.22051
R. Ismail
This paper focused on the behavior of the dam when exposed to seismic loading and ability of the dam to withstand the applied loads from various seismic events. The chosen concrete dam to be referred to in the two- dimensional analysis is Beris Dam located in Kedah, Malaysia. A nonlinear dynamic analysis is chosen to analyse the behavior of Beris Dam under selected ground motion. Analysis of the dam is performed using the finite element method by utilizing ABAQUS software. From the cracking analysis pattern, a crack appeared at the upstream face of the dam caused mainly by the excessive tensile stress. Based on the results, the displacement of the dam is increased with the increasing of ground motion data where the displacement occurred in the horizontal direction. The maximum stresses exerted by the dam structure do not exceed the allowable capacity of concrete dams. The stress behaviour of the dam was satisfactorily acceptable as the maximum normal stress and shear stress of the dam when numerous seismic loadings are applied do not exceed the allowable stress capacity which is 800 kN/m2.
{"title":"Seismic Behaviour of Beris Dam Under Six Earthquake Excitations by using Finite Element Method","authors":"R. Ismail","doi":"10.24191/jmeche.v20i2.22051","DOIUrl":"https://doi.org/10.24191/jmeche.v20i2.22051","url":null,"abstract":"This paper focused on the behavior of the dam when exposed to seismic loading and ability of the dam to withstand the applied loads from various seismic events. The chosen concrete dam to be referred to in the two- dimensional analysis is Beris Dam located in Kedah, Malaysia. A nonlinear dynamic analysis is chosen to analyse the behavior of Beris Dam under selected ground motion. Analysis of the dam is performed using the finite element method by utilizing ABAQUS software. From the cracking analysis pattern, a crack appeared at the upstream face of the dam caused mainly by the excessive tensile stress. Based on the results, the displacement of the dam is increased with the increasing of ground motion data where the displacement occurred in the horizontal direction. The maximum stresses exerted by the dam structure do not exceed the allowable capacity of concrete dams. The stress behaviour of the dam was satisfactorily acceptable as the maximum normal stress and shear stress of the dam when numerous seismic loadings are applied do not exceed the allowable stress capacity which is 800 kN/m2.","PeriodicalId":16166,"journal":{"name":"Journal of Mechanical Engineering and Sciences","volume":"12 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87404642","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 : 2023-04-15DOI: 10.24191/jmeche.v20i2.22058
N. Ibrahim
Concrete needs to be reinforced to improve its engineering qualities. Coconut fibres were employed for this study since they are widely accessible and come in big numbers. The study compares the qualities of plain concrete and concrete reinforced with coconut fibre based on a laboratory experiment. Better management of these waste fibres will result from using coconut fibres. Two types of coconut fibre treatment were employed – treatment with tap water and treatment with sodium hypochlorite. It is found in this study that adding 1% of coconut fibre does not increase the concrete strength after 7 and 14 days of curing. However, it was discovered that using 1% coconut fibres treated using tap water increased the compressive and flexural strength of the concrete after 28 days of curing by roughly 4% and 3%, respectively. Compressive and flexural strength development agrees very well with each other. Hence, it is concluded that 1% was the ideal fibre concentration (by weight of cement) to obtain a better 28th day of compressive and flexural strength, although not for 7 and 14 days. However, concrete with the highest strengths demonstrated a very low slump value, only 20 mm. A smaller or bigger slump value showed smaller concrete strengths.
{"title":"Concrete with Coconut Fibre Treated with Sodium Hypochlorite – Compressive and Flexural Strength","authors":"N. Ibrahim","doi":"10.24191/jmeche.v20i2.22058","DOIUrl":"https://doi.org/10.24191/jmeche.v20i2.22058","url":null,"abstract":"Concrete needs to be reinforced to improve its engineering qualities. Coconut fibres were employed for this study since they are widely accessible and come in big numbers. The study compares the qualities of plain concrete and concrete reinforced with coconut fibre based on a laboratory experiment. Better management of these waste fibres will result from using coconut fibres. Two types of coconut fibre treatment were employed – treatment with tap water and treatment with sodium hypochlorite. It is found in this study that adding 1% of coconut fibre does not increase the concrete strength after 7 and 14 days of curing. However, it was discovered that using 1% coconut fibres treated using tap water increased the compressive and flexural strength of the concrete after 28 days of curing by roughly 4% and 3%, respectively. Compressive and flexural strength development agrees very well with each other. Hence, it is concluded that 1% was the ideal fibre concentration (by weight of cement) to obtain a better 28th day of compressive and flexural strength, although not for 7 and 14 days. However, concrete with the highest strengths demonstrated a very low slump value, only 20 mm. A smaller or bigger slump value showed smaller concrete strengths.","PeriodicalId":16166,"journal":{"name":"Journal of Mechanical Engineering and Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89554286","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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