Pub Date : 2024-02-14DOI: 10.1177/09544089231223599
Jatoth Heeraman, Ravinder Kumar, P. Chaurasiya, T. Verma, Davendra Kumar Chauhan
Double pipe heat exchanger (DPHE) is a key component of a wide variety of fields where heat trans-mission is a necessity. The numerical simulation was carried out using ANSYS 16.0 within the operating Reynolds number ( Re) 6000 to 14,000 to explore and estimate the thermal performance of the heat exchangers (HEs). Computational fluid dynamic (CFD) analysis was performed for the tube tailored with tape twisted (TT) with dimples of Día = 6 mm, D/H Ratio = 1.5, 3 and 4.5, with twist ratio is 5.5. The gathered datasets were subsequently employed validate an artificial neural network (ANN) model, aiming to forecast Nusselt numbers and friction factor within a tube containing dimpled twisted tape inserts. The mean relative errors (MRE) between the predicted results, experimental data and numerical results for the Nusselt numbers and the friction factor were less than 3.30, 0.08 and 2.1 percentage, respectively. Consequently, the study suggests employing the combination of CFD and ANN models as a means to forecast the effectiveness of thermal systems in diverse engineering applications. The efficiency of heat transmission, frictional loss, flow rates and heat transfer rate were all determined using these quantitative simulations.
{"title":"Optimisation and comparison of performance parameters of a double pipe heat exchanger with dimpled twisted tapes using CFD and ANN","authors":"Jatoth Heeraman, Ravinder Kumar, P. Chaurasiya, T. Verma, Davendra Kumar Chauhan","doi":"10.1177/09544089231223599","DOIUrl":"https://doi.org/10.1177/09544089231223599","url":null,"abstract":"Double pipe heat exchanger (DPHE) is a key component of a wide variety of fields where heat trans-mission is a necessity. The numerical simulation was carried out using ANSYS 16.0 within the operating Reynolds number ( Re) 6000 to 14,000 to explore and estimate the thermal performance of the heat exchangers (HEs). Computational fluid dynamic (CFD) analysis was performed for the tube tailored with tape twisted (TT) with dimples of Día = 6 mm, D/H Ratio = 1.5, 3 and 4.5, with twist ratio is 5.5. The gathered datasets were subsequently employed validate an artificial neural network (ANN) model, aiming to forecast Nusselt numbers and friction factor within a tube containing dimpled twisted tape inserts. The mean relative errors (MRE) between the predicted results, experimental data and numerical results for the Nusselt numbers and the friction factor were less than 3.30, 0.08 and 2.1 percentage, respectively. Consequently, the study suggests employing the combination of CFD and ANN models as a means to forecast the effectiveness of thermal systems in diverse engineering applications. The efficiency of heat transmission, frictional loss, flow rates and heat transfer rate were all determined using these quantitative simulations.","PeriodicalId":506108,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering","volume":"48 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139778880","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 : 2024-02-14DOI: 10.1177/09544089231223599
Jatoth Heeraman, Ravinder Kumar, P. Chaurasiya, T. Verma, Davendra Kumar Chauhan
Double pipe heat exchanger (DPHE) is a key component of a wide variety of fields where heat trans-mission is a necessity. The numerical simulation was carried out using ANSYS 16.0 within the operating Reynolds number ( Re) 6000 to 14,000 to explore and estimate the thermal performance of the heat exchangers (HEs). Computational fluid dynamic (CFD) analysis was performed for the tube tailored with tape twisted (TT) with dimples of Día = 6 mm, D/H Ratio = 1.5, 3 and 4.5, with twist ratio is 5.5. The gathered datasets were subsequently employed validate an artificial neural network (ANN) model, aiming to forecast Nusselt numbers and friction factor within a tube containing dimpled twisted tape inserts. The mean relative errors (MRE) between the predicted results, experimental data and numerical results for the Nusselt numbers and the friction factor were less than 3.30, 0.08 and 2.1 percentage, respectively. Consequently, the study suggests employing the combination of CFD and ANN models as a means to forecast the effectiveness of thermal systems in diverse engineering applications. The efficiency of heat transmission, frictional loss, flow rates and heat transfer rate were all determined using these quantitative simulations.
{"title":"Optimisation and comparison of performance parameters of a double pipe heat exchanger with dimpled twisted tapes using CFD and ANN","authors":"Jatoth Heeraman, Ravinder Kumar, P. Chaurasiya, T. Verma, Davendra Kumar Chauhan","doi":"10.1177/09544089231223599","DOIUrl":"https://doi.org/10.1177/09544089231223599","url":null,"abstract":"Double pipe heat exchanger (DPHE) is a key component of a wide variety of fields where heat trans-mission is a necessity. The numerical simulation was carried out using ANSYS 16.0 within the operating Reynolds number ( Re) 6000 to 14,000 to explore and estimate the thermal performance of the heat exchangers (HEs). Computational fluid dynamic (CFD) analysis was performed for the tube tailored with tape twisted (TT) with dimples of Día = 6 mm, D/H Ratio = 1.5, 3 and 4.5, with twist ratio is 5.5. The gathered datasets were subsequently employed validate an artificial neural network (ANN) model, aiming to forecast Nusselt numbers and friction factor within a tube containing dimpled twisted tape inserts. The mean relative errors (MRE) between the predicted results, experimental data and numerical results for the Nusselt numbers and the friction factor were less than 3.30, 0.08 and 2.1 percentage, respectively. Consequently, the study suggests employing the combination of CFD and ANN models as a means to forecast the effectiveness of thermal systems in diverse engineering applications. The efficiency of heat transmission, frictional loss, flow rates and heat transfer rate were all determined using these quantitative simulations.","PeriodicalId":506108,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering","volume":"116 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139838714","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 : 2024-02-13DOI: 10.1177/09544089241229559
Weiji Qian, Xu Ou, Shengjie Yong, Yan Zheng
With the rapid development in rail transit industry in China, the energy supply of rail monitoring equipment has become a prominent problem, especially in some remote areas. The rail vibration caused by passing trains is a huge energy source. However, due to the characteristics of rail vibration (instantaneous, aperiodic and broadband excitation), the existing rail vibration energy harvesters can only collect rail vibration energy efficiently within a specific frequency range, the energy recovery efficiency is very low. In order to solve these problems, a multi-mode piezoelectric–electromagnetic composite energy harvester based on the rail vibration absorber has been presented in this paper. A model of the wheel–rail–vibration absorber system is established to simulate the rail vibration. In this model, the friction coupling between the wheel and rail has been considered. Under the same structural parameters and operating conditions, the predicted results of this model are consistent with the field-measured results. Base on this wheel–rail–vibration absorber model, numerical simulation analysis of the power generation performance of the composite energy harvester is carried out. The analysis results show that the output power of the multi-mode piezoelectric–electromagnetic composite energy harvester has a total of 6 peaks in the range of 0 to 600 Hz, with a maximum output power of 8.57 mW. Compared to existing vibration energy harvesters, the composite energy harvester has a wider energy harvesting frequency range and higher harvesting efficiency. The parameter analysis results show that the energy harvesting efficiency can be further improved by adjusting the structural parameters or the strain energy of the cantilever beam. This multi-mode piezoelectric–electromagnetic composite energy harvester is beneficial for improving the energy recovery efficiency of rail vibration. It effectively reduces the energy supply costs of the rail monitoring equipment.
{"title":"Study on the power generation performance of multi-mode piezoelectric–electromagnetic composite energy harvester based on rail vibration absorber","authors":"Weiji Qian, Xu Ou, Shengjie Yong, Yan Zheng","doi":"10.1177/09544089241229559","DOIUrl":"https://doi.org/10.1177/09544089241229559","url":null,"abstract":"With the rapid development in rail transit industry in China, the energy supply of rail monitoring equipment has become a prominent problem, especially in some remote areas. The rail vibration caused by passing trains is a huge energy source. However, due to the characteristics of rail vibration (instantaneous, aperiodic and broadband excitation), the existing rail vibration energy harvesters can only collect rail vibration energy efficiently within a specific frequency range, the energy recovery efficiency is very low. In order to solve these problems, a multi-mode piezoelectric–electromagnetic composite energy harvester based on the rail vibration absorber has been presented in this paper. A model of the wheel–rail–vibration absorber system is established to simulate the rail vibration. In this model, the friction coupling between the wheel and rail has been considered. Under the same structural parameters and operating conditions, the predicted results of this model are consistent with the field-measured results. Base on this wheel–rail–vibration absorber model, numerical simulation analysis of the power generation performance of the composite energy harvester is carried out. The analysis results show that the output power of the multi-mode piezoelectric–electromagnetic composite energy harvester has a total of 6 peaks in the range of 0 to 600 Hz, with a maximum output power of 8.57 mW. Compared to existing vibration energy harvesters, the composite energy harvester has a wider energy harvesting frequency range and higher harvesting efficiency. The parameter analysis results show that the energy harvesting efficiency can be further improved by adjusting the structural parameters or the strain energy of the cantilever beam. This multi-mode piezoelectric–electromagnetic composite energy harvester is beneficial for improving the energy recovery efficiency of rail vibration. It effectively reduces the energy supply costs of the rail monitoring equipment.","PeriodicalId":506108,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering","volume":"33 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139841004","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 : 2024-02-13DOI: 10.1177/09544089241231481
Saqib Ali, Shahnwaz Alam, Mohammad Nawaz Khan
Fan-shaped cavity microchannel heatsink with the combination of ribs is an effective configuration to dissipate large amounts of heat at the expense of lower pressure drop. However, the most effective location of circular ribs within a fan-shaped cavity which enhances the performance of a microchannel heat sink is still unknown. In this work, seven different structural units based on the ribs location in the cavity region such as ribs at the front of the cavities (RFC), at the back (RBC), at the centre (RCC), at the front and back (RFBC), at the left (RLC), at the right (RRC) and at the left and right (RLRC) are analysed for the range of Reynolds number from 100 to 500 and the results are compared with the microchannel with fan-shaped cavity only (MHFC) and plain rectangular microchannel heat sink on the basis of Nusselt number, interface temperature, pressure drop and performance factor. A notable finding of this study is identifying a rib as a disruption leading to the splitting of flow into two streams towards the arcuate region of the cavity and results in the enhanced mixing of the mainstream flow and the trapped fluid in the arcuate region. The maximum Nusselt number is exhibited by the RFBC with an increment of about 19% relative to the conventional centre location of the ribs in the cavity (RCC). At a lower Reynolds number, the Nusselt number of RLRC is lower than RCC and RBC however at Re > 300, the Nusselt number of RLRC is nearly equal to RCC whereas the minimum Nusselt number is associated with RRC and RLC among the microchannels having cavities and ribs. Along with the highest Nusselt number the largest value of pressure drop is also associated with RFBC whereas minimum pressure drop is accompanied by RRC and RLC.
{"title":"Effect of cylindrical ribs arrangement in the cavity region of the microchannel heatsink with a fan-shaped cavity","authors":"Saqib Ali, Shahnwaz Alam, Mohammad Nawaz Khan","doi":"10.1177/09544089241231481","DOIUrl":"https://doi.org/10.1177/09544089241231481","url":null,"abstract":"Fan-shaped cavity microchannel heatsink with the combination of ribs is an effective configuration to dissipate large amounts of heat at the expense of lower pressure drop. However, the most effective location of circular ribs within a fan-shaped cavity which enhances the performance of a microchannel heat sink is still unknown. In this work, seven different structural units based on the ribs location in the cavity region such as ribs at the front of the cavities (RFC), at the back (RBC), at the centre (RCC), at the front and back (RFBC), at the left (RLC), at the right (RRC) and at the left and right (RLRC) are analysed for the range of Reynolds number from 100 to 500 and the results are compared with the microchannel with fan-shaped cavity only (MHFC) and plain rectangular microchannel heat sink on the basis of Nusselt number, interface temperature, pressure drop and performance factor. A notable finding of this study is identifying a rib as a disruption leading to the splitting of flow into two streams towards the arcuate region of the cavity and results in the enhanced mixing of the mainstream flow and the trapped fluid in the arcuate region. The maximum Nusselt number is exhibited by the RFBC with an increment of about 19% relative to the conventional centre location of the ribs in the cavity (RCC). At a lower Reynolds number, the Nusselt number of RLRC is lower than RCC and RBC however at Re > 300, the Nusselt number of RLRC is nearly equal to RCC whereas the minimum Nusselt number is associated with RRC and RLC among the microchannels having cavities and ribs. Along with the highest Nusselt number the largest value of pressure drop is also associated with RFBC whereas minimum pressure drop is accompanied by RRC and RLC.","PeriodicalId":506108,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering","volume":"618 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139841248","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 : 2024-02-13DOI: 10.1177/09544089241226762
M. Nag, Abhishek Shrivastava
Coir fiber crystallinity is crucial since it widens the range of possible uses for natural fiber. To increase the crystallinity of coir fiber, the study describes an easy-to-use, simple-to-implement method that is cost-effective, eco-friendly, and highly productive. With the help of dodecyl methacrylate disperson, hydrocarbon molecules of varying chain lengths are covalently attached to the surface of coir fibers, modulating their surface wettability. There are a few different long-chain hydrocarbon compounds employed, including n-butyl methacrylate, n-octyl acrylate, and dodecyl methacrylate (DM), but DM has shown to be the most effective. The degree of grafting yield alteration is determined gravimetrically. It has been found that grafting yields of 28–30 wt.% can be used to convert hydrophilic coir fibers into water repellent crystalline fibers (water contact angle 148°). A total of 15 nm of dispersion, a disperson rate of 2 nm/min, DM concentration of 20%, and water content of 10% are fixed as key reaction parameters. Thermal and mechanical analyses show no significant changes in the fiber structure during alteration. The grafting and changes in surface wettability are well supported by the surface morphology of pure and modified coir fiber, which can be seen using scanning electron microscopy.
{"title":"Dodecyl methacrylate (DM) dispersion-assisted surface modification approach for increasing crystallinity of coir fibers","authors":"M. Nag, Abhishek Shrivastava","doi":"10.1177/09544089241226762","DOIUrl":"https://doi.org/10.1177/09544089241226762","url":null,"abstract":"Coir fiber crystallinity is crucial since it widens the range of possible uses for natural fiber. To increase the crystallinity of coir fiber, the study describes an easy-to-use, simple-to-implement method that is cost-effective, eco-friendly, and highly productive. With the help of dodecyl methacrylate disperson, hydrocarbon molecules of varying chain lengths are covalently attached to the surface of coir fibers, modulating their surface wettability. There are a few different long-chain hydrocarbon compounds employed, including n-butyl methacrylate, n-octyl acrylate, and dodecyl methacrylate (DM), but DM has shown to be the most effective. The degree of grafting yield alteration is determined gravimetrically. It has been found that grafting yields of 28–30 wt.% can be used to convert hydrophilic coir fibers into water repellent crystalline fibers (water contact angle 148°). A total of 15 nm of dispersion, a disperson rate of 2 nm/min, DM concentration of 20%, and water content of 10% are fixed as key reaction parameters. Thermal and mechanical analyses show no significant changes in the fiber structure during alteration. The grafting and changes in surface wettability are well supported by the surface morphology of pure and modified coir fiber, which can be seen using scanning electron microscopy.","PeriodicalId":506108,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering","volume":"160 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139840643","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 : 2024-02-13DOI: 10.1177/09544089241230866
Nitin Kumar Mamidi, K. Balasubramanian, K. Kupireddi, Chandramohan V.P., Poh-Seng Lee, C. C. Kong
Microchannel-based cooling methods have been found extremely suitable for compact heat exchangers. High rate of heat extraction is always associated with pressure drop penalty which lowers the overall performance of the device. Heat sinks that would deliver high thermal performance at relatively lower pumping are highly desirable. In the present article, curved microchannels with secondary flow channels are numerically investigated to minimize the pressure loss and enhance the heat transfer simultaneously. Uniform heat flux boundary condition with Reynolds number ranging from 100 to 225 is considered for analysis. Seven models having secondary flow channel orientation angles varying from 30° to 42° are compared with radially curved microchannel (RCMC) having central inlet and horizontal radial outlet arrangement. A greater increase in Nu is observed in the secondary channel with a higher orientation angle, primarily attributed to enhanced fluid mixing. Results revealed a maximum Nusselt number increase of 25.72% for RCMC with secondary flow (RCMCSF) when compared to RCMC with reduction in pressure drop penalty at the same time. At a Reynolds number of 100, the RCMCSF 30D demonstrated the maximum pressure loss reduction, which amounted to 23.91% compared to RCMC. The temperature of the wall in contact with the fluid exhibits a decreasing trend with an increase in Reynolds number (Re). This occurrence is attributed to improved fluid mixing, resulting from higher flow rates. The intensified velocity vectors in the cross-plane contribute to this enhanced mixing and subsequent decline in wall temperature. Reduction in average wall temperature up to 3.43°C is noted for RCMCSF when compared to RCMC. Of all the designs considered, radial curved microchannel with a secondary channel orientation angle of 40° shows enhanced thermal hydraulic performance with performance factor equal to 1.31.
{"title":"Enhancement in thermo hydraulic performance of radially curved microchannel with secondary flow","authors":"Nitin Kumar Mamidi, K. Balasubramanian, K. Kupireddi, Chandramohan V.P., Poh-Seng Lee, C. C. Kong","doi":"10.1177/09544089241230866","DOIUrl":"https://doi.org/10.1177/09544089241230866","url":null,"abstract":"Microchannel-based cooling methods have been found extremely suitable for compact heat exchangers. High rate of heat extraction is always associated with pressure drop penalty which lowers the overall performance of the device. Heat sinks that would deliver high thermal performance at relatively lower pumping are highly desirable. In the present article, curved microchannels with secondary flow channels are numerically investigated to minimize the pressure loss and enhance the heat transfer simultaneously. Uniform heat flux boundary condition with Reynolds number ranging from 100 to 225 is considered for analysis. Seven models having secondary flow channel orientation angles varying from 30° to 42° are compared with radially curved microchannel (RCMC) having central inlet and horizontal radial outlet arrangement. A greater increase in Nu is observed in the secondary channel with a higher orientation angle, primarily attributed to enhanced fluid mixing. Results revealed a maximum Nusselt number increase of 25.72% for RCMC with secondary flow (RCMCSF) when compared to RCMC with reduction in pressure drop penalty at the same time. At a Reynolds number of 100, the RCMCSF 30D demonstrated the maximum pressure loss reduction, which amounted to 23.91% compared to RCMC. The temperature of the wall in contact with the fluid exhibits a decreasing trend with an increase in Reynolds number (Re). This occurrence is attributed to improved fluid mixing, resulting from higher flow rates. The intensified velocity vectors in the cross-plane contribute to this enhanced mixing and subsequent decline in wall temperature. Reduction in average wall temperature up to 3.43°C is noted for RCMCSF when compared to RCMC. Of all the designs considered, radial curved microchannel with a secondary channel orientation angle of 40° shows enhanced thermal hydraulic performance with performance factor equal to 1.31.","PeriodicalId":506108,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering","volume":"54 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139840348","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 : 2024-02-13DOI: 10.1177/09544089241226762
M. Nag, Abhishek Shrivastava
Coir fiber crystallinity is crucial since it widens the range of possible uses for natural fiber. To increase the crystallinity of coir fiber, the study describes an easy-to-use, simple-to-implement method that is cost-effective, eco-friendly, and highly productive. With the help of dodecyl methacrylate disperson, hydrocarbon molecules of varying chain lengths are covalently attached to the surface of coir fibers, modulating their surface wettability. There are a few different long-chain hydrocarbon compounds employed, including n-butyl methacrylate, n-octyl acrylate, and dodecyl methacrylate (DM), but DM has shown to be the most effective. The degree of grafting yield alteration is determined gravimetrically. It has been found that grafting yields of 28–30 wt.% can be used to convert hydrophilic coir fibers into water repellent crystalline fibers (water contact angle 148°). A total of 15 nm of dispersion, a disperson rate of 2 nm/min, DM concentration of 20%, and water content of 10% are fixed as key reaction parameters. Thermal and mechanical analyses show no significant changes in the fiber structure during alteration. The grafting and changes in surface wettability are well supported by the surface morphology of pure and modified coir fiber, which can be seen using scanning electron microscopy.
{"title":"Dodecyl methacrylate (DM) dispersion-assisted surface modification approach for increasing crystallinity of coir fibers","authors":"M. Nag, Abhishek Shrivastava","doi":"10.1177/09544089241226762","DOIUrl":"https://doi.org/10.1177/09544089241226762","url":null,"abstract":"Coir fiber crystallinity is crucial since it widens the range of possible uses for natural fiber. To increase the crystallinity of coir fiber, the study describes an easy-to-use, simple-to-implement method that is cost-effective, eco-friendly, and highly productive. With the help of dodecyl methacrylate disperson, hydrocarbon molecules of varying chain lengths are covalently attached to the surface of coir fibers, modulating their surface wettability. There are a few different long-chain hydrocarbon compounds employed, including n-butyl methacrylate, n-octyl acrylate, and dodecyl methacrylate (DM), but DM has shown to be the most effective. The degree of grafting yield alteration is determined gravimetrically. It has been found that grafting yields of 28–30 wt.% can be used to convert hydrophilic coir fibers into water repellent crystalline fibers (water contact angle 148°). A total of 15 nm of dispersion, a disperson rate of 2 nm/min, DM concentration of 20%, and water content of 10% are fixed as key reaction parameters. Thermal and mechanical analyses show no significant changes in the fiber structure during alteration. The grafting and changes in surface wettability are well supported by the surface morphology of pure and modified coir fiber, which can be seen using scanning electron microscopy.","PeriodicalId":506108,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering","volume":"128 46","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139780930","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 : 2024-02-13DOI: 10.1177/09544089241231481
Saqib Ali, Shahnwaz Alam, Mohammad Nawaz Khan
Fan-shaped cavity microchannel heatsink with the combination of ribs is an effective configuration to dissipate large amounts of heat at the expense of lower pressure drop. However, the most effective location of circular ribs within a fan-shaped cavity which enhances the performance of a microchannel heat sink is still unknown. In this work, seven different structural units based on the ribs location in the cavity region such as ribs at the front of the cavities (RFC), at the back (RBC), at the centre (RCC), at the front and back (RFBC), at the left (RLC), at the right (RRC) and at the left and right (RLRC) are analysed for the range of Reynolds number from 100 to 500 and the results are compared with the microchannel with fan-shaped cavity only (MHFC) and plain rectangular microchannel heat sink on the basis of Nusselt number, interface temperature, pressure drop and performance factor. A notable finding of this study is identifying a rib as a disruption leading to the splitting of flow into two streams towards the arcuate region of the cavity and results in the enhanced mixing of the mainstream flow and the trapped fluid in the arcuate region. The maximum Nusselt number is exhibited by the RFBC with an increment of about 19% relative to the conventional centre location of the ribs in the cavity (RCC). At a lower Reynolds number, the Nusselt number of RLRC is lower than RCC and RBC however at Re > 300, the Nusselt number of RLRC is nearly equal to RCC whereas the minimum Nusselt number is associated with RRC and RLC among the microchannels having cavities and ribs. Along with the highest Nusselt number the largest value of pressure drop is also associated with RFBC whereas minimum pressure drop is accompanied by RRC and RLC.
{"title":"Effect of cylindrical ribs arrangement in the cavity region of the microchannel heatsink with a fan-shaped cavity","authors":"Saqib Ali, Shahnwaz Alam, Mohammad Nawaz Khan","doi":"10.1177/09544089241231481","DOIUrl":"https://doi.org/10.1177/09544089241231481","url":null,"abstract":"Fan-shaped cavity microchannel heatsink with the combination of ribs is an effective configuration to dissipate large amounts of heat at the expense of lower pressure drop. However, the most effective location of circular ribs within a fan-shaped cavity which enhances the performance of a microchannel heat sink is still unknown. In this work, seven different structural units based on the ribs location in the cavity region such as ribs at the front of the cavities (RFC), at the back (RBC), at the centre (RCC), at the front and back (RFBC), at the left (RLC), at the right (RRC) and at the left and right (RLRC) are analysed for the range of Reynolds number from 100 to 500 and the results are compared with the microchannel with fan-shaped cavity only (MHFC) and plain rectangular microchannel heat sink on the basis of Nusselt number, interface temperature, pressure drop and performance factor. A notable finding of this study is identifying a rib as a disruption leading to the splitting of flow into two streams towards the arcuate region of the cavity and results in the enhanced mixing of the mainstream flow and the trapped fluid in the arcuate region. The maximum Nusselt number is exhibited by the RFBC with an increment of about 19% relative to the conventional centre location of the ribs in the cavity (RCC). At a lower Reynolds number, the Nusselt number of RLRC is lower than RCC and RBC however at Re > 300, the Nusselt number of RLRC is nearly equal to RCC whereas the minimum Nusselt number is associated with RRC and RLC among the microchannels having cavities and ribs. Along with the highest Nusselt number the largest value of pressure drop is also associated with RFBC whereas minimum pressure drop is accompanied by RRC and RLC.","PeriodicalId":506108,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering","volume":"75 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139781400","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 : 2024-02-13DOI: 10.1177/09544089241229559
Weiji Qian, Xu Ou, Shengjie Yong, Yan Zheng
With the rapid development in rail transit industry in China, the energy supply of rail monitoring equipment has become a prominent problem, especially in some remote areas. The rail vibration caused by passing trains is a huge energy source. However, due to the characteristics of rail vibration (instantaneous, aperiodic and broadband excitation), the existing rail vibration energy harvesters can only collect rail vibration energy efficiently within a specific frequency range, the energy recovery efficiency is very low. In order to solve these problems, a multi-mode piezoelectric–electromagnetic composite energy harvester based on the rail vibration absorber has been presented in this paper. A model of the wheel–rail–vibration absorber system is established to simulate the rail vibration. In this model, the friction coupling between the wheel and rail has been considered. Under the same structural parameters and operating conditions, the predicted results of this model are consistent with the field-measured results. Base on this wheel–rail–vibration absorber model, numerical simulation analysis of the power generation performance of the composite energy harvester is carried out. The analysis results show that the output power of the multi-mode piezoelectric–electromagnetic composite energy harvester has a total of 6 peaks in the range of 0 to 600 Hz, with a maximum output power of 8.57 mW. Compared to existing vibration energy harvesters, the composite energy harvester has a wider energy harvesting frequency range and higher harvesting efficiency. The parameter analysis results show that the energy harvesting efficiency can be further improved by adjusting the structural parameters or the strain energy of the cantilever beam. This multi-mode piezoelectric–electromagnetic composite energy harvester is beneficial for improving the energy recovery efficiency of rail vibration. It effectively reduces the energy supply costs of the rail monitoring equipment.
{"title":"Study on the power generation performance of multi-mode piezoelectric–electromagnetic composite energy harvester based on rail vibration absorber","authors":"Weiji Qian, Xu Ou, Shengjie Yong, Yan Zheng","doi":"10.1177/09544089241229559","DOIUrl":"https://doi.org/10.1177/09544089241229559","url":null,"abstract":"With the rapid development in rail transit industry in China, the energy supply of rail monitoring equipment has become a prominent problem, especially in some remote areas. The rail vibration caused by passing trains is a huge energy source. However, due to the characteristics of rail vibration (instantaneous, aperiodic and broadband excitation), the existing rail vibration energy harvesters can only collect rail vibration energy efficiently within a specific frequency range, the energy recovery efficiency is very low. In order to solve these problems, a multi-mode piezoelectric–electromagnetic composite energy harvester based on the rail vibration absorber has been presented in this paper. A model of the wheel–rail–vibration absorber system is established to simulate the rail vibration. In this model, the friction coupling between the wheel and rail has been considered. Under the same structural parameters and operating conditions, the predicted results of this model are consistent with the field-measured results. Base on this wheel–rail–vibration absorber model, numerical simulation analysis of the power generation performance of the composite energy harvester is carried out. The analysis results show that the output power of the multi-mode piezoelectric–electromagnetic composite energy harvester has a total of 6 peaks in the range of 0 to 600 Hz, with a maximum output power of 8.57 mW. Compared to existing vibration energy harvesters, the composite energy harvester has a wider energy harvesting frequency range and higher harvesting efficiency. The parameter analysis results show that the energy harvesting efficiency can be further improved by adjusting the structural parameters or the strain energy of the cantilever beam. This multi-mode piezoelectric–electromagnetic composite energy harvester is beneficial for improving the energy recovery efficiency of rail vibration. It effectively reduces the energy supply costs of the rail monitoring equipment.","PeriodicalId":506108,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering","volume":"102 23","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139781342","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 : 2024-02-13DOI: 10.1177/09544089241230866
Nitin Kumar Mamidi, K. Balasubramanian, K. Kupireddi, Chandramohan V.P., Poh-Seng Lee, C. C. Kong
Microchannel-based cooling methods have been found extremely suitable for compact heat exchangers. High rate of heat extraction is always associated with pressure drop penalty which lowers the overall performance of the device. Heat sinks that would deliver high thermal performance at relatively lower pumping are highly desirable. In the present article, curved microchannels with secondary flow channels are numerically investigated to minimize the pressure loss and enhance the heat transfer simultaneously. Uniform heat flux boundary condition with Reynolds number ranging from 100 to 225 is considered for analysis. Seven models having secondary flow channel orientation angles varying from 30° to 42° are compared with radially curved microchannel (RCMC) having central inlet and horizontal radial outlet arrangement. A greater increase in Nu is observed in the secondary channel with a higher orientation angle, primarily attributed to enhanced fluid mixing. Results revealed a maximum Nusselt number increase of 25.72% for RCMC with secondary flow (RCMCSF) when compared to RCMC with reduction in pressure drop penalty at the same time. At a Reynolds number of 100, the RCMCSF 30D demonstrated the maximum pressure loss reduction, which amounted to 23.91% compared to RCMC. The temperature of the wall in contact with the fluid exhibits a decreasing trend with an increase in Reynolds number (Re). This occurrence is attributed to improved fluid mixing, resulting from higher flow rates. The intensified velocity vectors in the cross-plane contribute to this enhanced mixing and subsequent decline in wall temperature. Reduction in average wall temperature up to 3.43°C is noted for RCMCSF when compared to RCMC. Of all the designs considered, radial curved microchannel with a secondary channel orientation angle of 40° shows enhanced thermal hydraulic performance with performance factor equal to 1.31.
{"title":"Enhancement in thermo hydraulic performance of radially curved microchannel with secondary flow","authors":"Nitin Kumar Mamidi, K. Balasubramanian, K. Kupireddi, Chandramohan V.P., Poh-Seng Lee, C. C. Kong","doi":"10.1177/09544089241230866","DOIUrl":"https://doi.org/10.1177/09544089241230866","url":null,"abstract":"Microchannel-based cooling methods have been found extremely suitable for compact heat exchangers. High rate of heat extraction is always associated with pressure drop penalty which lowers the overall performance of the device. Heat sinks that would deliver high thermal performance at relatively lower pumping are highly desirable. In the present article, curved microchannels with secondary flow channels are numerically investigated to minimize the pressure loss and enhance the heat transfer simultaneously. Uniform heat flux boundary condition with Reynolds number ranging from 100 to 225 is considered for analysis. Seven models having secondary flow channel orientation angles varying from 30° to 42° are compared with radially curved microchannel (RCMC) having central inlet and horizontal radial outlet arrangement. A greater increase in Nu is observed in the secondary channel with a higher orientation angle, primarily attributed to enhanced fluid mixing. Results revealed a maximum Nusselt number increase of 25.72% for RCMC with secondary flow (RCMCSF) when compared to RCMC with reduction in pressure drop penalty at the same time. At a Reynolds number of 100, the RCMCSF 30D demonstrated the maximum pressure loss reduction, which amounted to 23.91% compared to RCMC. The temperature of the wall in contact with the fluid exhibits a decreasing trend with an increase in Reynolds number (Re). This occurrence is attributed to improved fluid mixing, resulting from higher flow rates. The intensified velocity vectors in the cross-plane contribute to this enhanced mixing and subsequent decline in wall temperature. Reduction in average wall temperature up to 3.43°C is noted for RCMCSF when compared to RCMC. Of all the designs considered, radial curved microchannel with a secondary channel orientation angle of 40° shows enhanced thermal hydraulic performance with performance factor equal to 1.31.","PeriodicalId":506108,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering","volume":"62 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139780379","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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