Pub Date : 2024-04-01DOI: 10.37934/arfmts.115.2.5060
Omar Ahmed Al-Sharif, Ahmed Emam Newir, Mohamed Aly Halawa
Predicting thermal preferences and ensuring comfort through machine learning is a highly active research field that has attracted significant attention from researchers aiming to achieve accurate forecasting and a deeper understanding of human thermal comfort in buildings. The primary objective of this study is to develop machine learning models for predicting thermal preference using the ASHRAE Global Thermal Comfort Database II. Additionally, the algorithms developed in this study can serve as valuable groundwork for transferring the acquired knowledge to develop personalized machine learning models, thereby enhancing individualized comfort. To enhance the dataset's accuracy and reliability, rigorous data exploration and preprocessing were executed. A comparative analysis of diverse machine learning algorithms was conducted, revealing that ensemble-based methods, namely Random Forest, Extra Trees, LightGBM, CatBoost, Gradient Boosting Machine, and XGBoost, exhibited superior performance in predicting thermal preferences. The accuracy of these ensemble models was further refined through hyperparameter optimization using the Optuna framework. This optimization led to a notable improvement, increased the model accuracy from 65% for traditional machine learning algorithms to 70% for the optimized ensemble algorithms.
{"title":"Predicting Thermal Preferences - A Comparative Analysis of Machine Learning Algorithms using ASHRAE Global Thermal Comfort Database II","authors":"Omar Ahmed Al-Sharif, Ahmed Emam Newir, Mohamed Aly Halawa","doi":"10.37934/arfmts.115.2.5060","DOIUrl":"https://doi.org/10.37934/arfmts.115.2.5060","url":null,"abstract":"Predicting thermal preferences and ensuring comfort through machine learning is a highly active research field that has attracted significant attention from researchers aiming to achieve accurate forecasting and a deeper understanding of human thermal comfort in buildings. The primary objective of this study is to develop machine learning models for predicting thermal preference using the ASHRAE Global Thermal Comfort Database II. Additionally, the algorithms developed in this study can serve as valuable groundwork for transferring the acquired knowledge to develop personalized machine learning models, thereby enhancing individualized comfort. To enhance the dataset's accuracy and reliability, rigorous data exploration and preprocessing were executed. A comparative analysis of diverse machine learning algorithms was conducted, revealing that ensemble-based methods, namely Random Forest, Extra Trees, LightGBM, CatBoost, Gradient Boosting Machine, and XGBoost, exhibited superior performance in predicting thermal preferences. The accuracy of these ensemble models was further refined through hyperparameter optimization using the Optuna framework. This optimization led to a notable improvement, increased the model accuracy from 65% for traditional machine learning algorithms to 70% for the optimized ensemble algorithms.","PeriodicalId":37460,"journal":{"name":"Journal of Advanced Research in Fluid Mechanics and Thermal Sciences","volume":"248 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140781451","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 : 2024-04-01DOI: 10.37934/arfmts.115.2.112
Azman Hafiidz Aji, Fatimah Al Zahrah Mohd Saat, Fadhilah Shikh Anuar, Patcharin Saechan
Induced acoustic streaming flow in thermoacoustic systems occurs due to acoustic vibrations, causing changes to the mean flow in the systems. This phenomenon creates a tendency to generate net fluid flow that can cause energy change within certain areas inside the system. However, the effects of the entire system’s vibrations on the flow streaming are not yet fully understood, yet it is important for a more effective operation. This study experimentally investigated the flow streaming resulting from vibration in a standing-wave thermoacoustic test rig with a flow frequency of 23.6 Hz. The existence of flow streaming due to vibration which was not counted in the theoretical formula is shown and indicated by experimental values. The result shows that there is a correlation between the amplitude of the drive ratio (DR) and the velocity of the oscillation of the flow. Upon examining both the theoretical and the practical evidence, it becomes clear that there exists a marginal flow velocity in directions other than the main flow due to the vibration of resonator’s wall as measured at the intake and outflow areas of the stack. This marginal flow velocity amplifies as the drive ratio of flow increases and it may potentially explain the observed difference between measured flow amplitude and the theoretical value.
{"title":"Vibration-Induced Flow and Streaming in Oscillatory Flow of Thermoacoustics","authors":"Azman Hafiidz Aji, Fatimah Al Zahrah Mohd Saat, Fadhilah Shikh Anuar, Patcharin Saechan","doi":"10.37934/arfmts.115.2.112","DOIUrl":"https://doi.org/10.37934/arfmts.115.2.112","url":null,"abstract":"Induced acoustic streaming flow in thermoacoustic systems occurs due to acoustic vibrations, causing changes to the mean flow in the systems. This phenomenon creates a tendency to generate net fluid flow that can cause energy change within certain areas inside the system. However, the effects of the entire system’s vibrations on the flow streaming are not yet fully understood, yet it is important for a more effective operation. This study experimentally investigated the flow streaming resulting from vibration in a standing-wave thermoacoustic test rig with a flow frequency of 23.6 Hz. The existence of flow streaming due to vibration which was not counted in the theoretical formula is shown and indicated by experimental values. The result shows that there is a correlation between the amplitude of the drive ratio (DR) and the velocity of the oscillation of the flow. Upon examining both the theoretical and the practical evidence, it becomes clear that there exists a marginal flow velocity in directions other than the main flow due to the vibration of resonator’s wall as measured at the intake and outflow areas of the stack. This marginal flow velocity amplifies as the drive ratio of flow increases and it may potentially explain the observed difference between measured flow amplitude and the theoretical value.","PeriodicalId":37460,"journal":{"name":"Journal of Advanced Research in Fluid Mechanics and Thermal Sciences","volume":"186 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140764510","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 : 2024-04-01DOI: 10.37934/arfmts.115.2.96102
Hery Sunarsono, Hazimah, Sari Rahmiati, Mohd Sapuan Salit, Ahmad Ilyas Rushdan, Fiqri Ardi Azhari
The preparation stages that precede the final treatment with a chemical treatment like alkali determine the physical characteristics of ramie fibres. It modified the hydroxyl group which is responsible for the hydrogen bonding of the fibres. This work examined the pre-treatment of ramie fibres with acetone followed by alkali or hot alkali with various concentrations. The immersion of ramie fibres in certain percentages of sodium hydroxide solution resulted in a good performance of their physical characteristics. The ramie fibres treated with 10% NaOH exhibit the best dispersion stability and low agglomeration or precipitation in water with an amount of 14%. When alkali is applied to ramie fibres, the hydrophilic group on their surface grows, potentially improving the fibre's capacity to absorb water. However, when the concentration is increased to 15%, the dispersion stability of sodium hydroxide performs less well. The fibres' ability to absorb water was diminished and they became brittle due to a high alkali content. In addition to the aforementioned characteristics, the properties of precipitation and water absorption were unaffected by the hot alkaline process for all samples. The hot alkali process (80°C) was not able to generate a further breakdown of hydrogen bonds of the fibres.
{"title":"Effect of Various Concentrations of Sodium Hydroxide/Hot Alkali Treatment on the Physical Properties of Ramie Fibres","authors":"Hery Sunarsono, Hazimah, Sari Rahmiati, Mohd Sapuan Salit, Ahmad Ilyas Rushdan, Fiqri Ardi Azhari","doi":"10.37934/arfmts.115.2.96102","DOIUrl":"https://doi.org/10.37934/arfmts.115.2.96102","url":null,"abstract":"The preparation stages that precede the final treatment with a chemical treatment like alkali determine the physical characteristics of ramie fibres. It modified the hydroxyl group which is responsible for the hydrogen bonding of the fibres. This work examined the pre-treatment of ramie fibres with acetone followed by alkali or hot alkali with various concentrations. The immersion of ramie fibres in certain percentages of sodium hydroxide solution resulted in a good performance of their physical characteristics. The ramie fibres treated with 10% NaOH exhibit the best dispersion stability and low agglomeration or precipitation in water with an amount of 14%. When alkali is applied to ramie fibres, the hydrophilic group on their surface grows, potentially improving the fibre's capacity to absorb water. However, when the concentration is increased to 15%, the dispersion stability of sodium hydroxide performs less well. The fibres' ability to absorb water was diminished and they became brittle due to a high alkali content. In addition to the aforementioned characteristics, the properties of precipitation and water absorption were unaffected by the hot alkaline process for all samples. The hot alkali process (80°C) was not able to generate a further breakdown of hydrogen bonds of the fibres.","PeriodicalId":37460,"journal":{"name":"Journal of Advanced Research in Fluid Mechanics and Thermal Sciences","volume":"367 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140788648","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}
The aim of this study is to analyze the effects of activation energy and thermal diffusion an unsteady MHD reactive Maxwell fluid flow past a porous stretching sheet in the presence of Brownian motion, Thermophoresis and nonlinear thermal. The non-linear partial differential equations that govern the fluid flow have been transformed into a two-point boundary value problem using similarity variables and then solved numerically by fourth order Runge–Kutta method with shooting technique. Graphical results are discussed for non-dimensional velocity, temperature and concentration profiles while numerical values of the skin friction, Nusselt number and Sherwood number are presented in tabular form for various values of parameters controlling the flow system. The present study is compared with the previous literature and found to be in good agreement.
{"title":"Heat and Mass Transfer in Unsteady Radiating MHD Flow of a Maxwell Fluid with a Porous Vertically Stretching Sheet in the Presence of Activation Energy and Thermal Diffusion Effects","authors":"Damodara Reddy Annapureddy, Sarada Devi Puliyeddula, Nagaraju Vellanki, Kalyan Kumar Palaparthi","doi":"10.37934/arfmts.115.2.158177","DOIUrl":"https://doi.org/10.37934/arfmts.115.2.158177","url":null,"abstract":"The aim of this study is to analyze the effects of activation energy and thermal diffusion an unsteady MHD reactive Maxwell fluid flow past a porous stretching sheet in the presence of Brownian motion, Thermophoresis and nonlinear thermal. The non-linear partial differential equations that govern the fluid flow have been transformed into a two-point boundary value problem using similarity variables and then solved numerically by fourth order Runge–Kutta method with shooting technique. Graphical results are discussed for non-dimensional velocity, temperature and concentration profiles while numerical values of the skin friction, Nusselt number and Sherwood number are presented in tabular form for various values of parameters controlling the flow system. The present study is compared with the previous literature and found to be in good agreement.","PeriodicalId":37460,"journal":{"name":"Journal of Advanced Research in Fluid Mechanics and Thermal Sciences","volume":"89 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140794207","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 : 2024-04-01DOI: 10.37934/arfmts.115.2.8395
Saleh Umar Abubakar, Siti Amely Jumaat, Babangida Yakubu, Yau Shuaibu Haruna, Suleiman Abdulrahman
Globally people are faced with difficulties in environmental pollution, increasing power costs, and global warming. As such researchers are focusing on enhancing energy-harvesting using thermoelectric generators for power generation to lessen the difficulties. Through the Seebeck effect, thermoelectric generators (TEGs) have proven their ability to convert thermal energy into electric power. Given the unique benefits they present, thermoelectric generators have arisen in the recent decade as a possible alternative to other green power generation technologies. A thermoelectric generator (TEG) is a solid-state device that converts thermal energy into electrical energy. TEG consists of elements of p and n-type semiconductors, connected thermally in parallel and electrically in series. In this paper, one hundred and ninety-two thermoelectric generators connected in series and parallel were used to investigate the thermal energy potential at the roof and attic area for domestic application for 20 days from the falling solar radiation on a residential prototype in Bashar, Wase Local government area of Plateau State. A theoretical analysis was used in determining the average output power (P) due to the delta T across the thermoelectric generator module junction. The load resistance value of the thermoelectric generator configuration was evaluated. The results show that the TEG generated power output ranging from 217 mW to 1.99 W throughout the day, 5.97 mW to 13.8 mW in the morning, and 6.8 mW to 36.9 mW in the evening. Furthermore, The finding also reveals that the attic side has the capacity to store thermal energy, which can be harnessed owing to the fast heat transfer to the surroundings during the convection process. In conclusion, solar irradiance has a major impact on the system.
在全球范围内，人们面临着环境污染、电力成本增加和全球变暖等困难。因此，研究人员正专注于利用热电发电机加强能量收集，以减少发电困难。通过塞贝克效应，热电发电机（TEG）已经证明了其将热能转化为电能的能力。鉴于其独特的优势，近十年来，热电发电机已成为其他绿色发电技术的可能替代品。热电发电机（TEG）是一种能将热能转化为电能的固态装置。TEG 由热并联和电串联的 p 型和 n 型半导体元件组成。本文使用了 192 台串联和并联的热电发生器，对高原州瓦塞地方政府地区巴沙尔的一个住宅原型进行了为期 20 天的太阳辐射下降情况下屋顶和阁楼区域的热能潜力调查。通过理论分析，确定了热电模块结点上的三角洲 T 所产生的平均输出功率 (P)。对热电发电机配置的负载电阻值进行了评估。结果表明，热电发生器全天产生的功率输出范围为 217 mW 至 1.99 W，上午为 5.97 mW 至 13.8 mW，傍晚为 6.8 mW 至 36.9 mW。此外，研究结果还表明，阁楼一侧具有储存热能的能力，由于在对流过程中热量能快速传递到周围环境，因此可以利用这些热能。总之，太阳辐照度对系统有重大影响。
{"title":"Thermoelectric Energy Harvesting from the Roof and Attics of a Building","authors":"Saleh Umar Abubakar, Siti Amely Jumaat, Babangida Yakubu, Yau Shuaibu Haruna, Suleiman Abdulrahman","doi":"10.37934/arfmts.115.2.8395","DOIUrl":"https://doi.org/10.37934/arfmts.115.2.8395","url":null,"abstract":"Globally people are faced with difficulties in environmental pollution, increasing power costs, and global warming. As such researchers are focusing on enhancing energy-harvesting using thermoelectric generators for power generation to lessen the difficulties. Through the Seebeck effect, thermoelectric generators (TEGs) have proven their ability to convert thermal energy into electric power. Given the unique benefits they present, thermoelectric generators have arisen in the recent decade as a possible alternative to other green power generation technologies. A thermoelectric generator (TEG) is a solid-state device that converts thermal energy into electrical energy. TEG consists of elements of p and n-type semiconductors, connected thermally in parallel and electrically in series. In this paper, one hundred and ninety-two thermoelectric generators connected in series and parallel were used to investigate the thermal energy potential at the roof and attic area for domestic application for 20 days from the falling solar radiation on a residential prototype in Bashar, Wase Local government area of Plateau State. A theoretical analysis was used in determining the average output power (P) due to the delta T across the thermoelectric generator module junction. The load resistance value of the thermoelectric generator configuration was evaluated. The results show that the TEG generated power output ranging from 217 mW to 1.99 W throughout the day, 5.97 mW to 13.8 mW in the morning, and 6.8 mW to 36.9 mW in the evening. Furthermore, The finding also reveals that the attic side has the capacity to store thermal energy, which can be harnessed owing to the fast heat transfer to the surroundings during the convection process. In conclusion, solar irradiance has a major impact on the system.","PeriodicalId":37460,"journal":{"name":"Journal of Advanced Research in Fluid Mechanics and Thermal Sciences","volume":"44 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140771583","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 : 2024-04-01DOI: 10.37934/arfmts.115.2.6169
Mohd Arif Rosli, Muhamad Shahril Mohd Abdullah, Azian Hariri, Amir Abdullah Muhamad Damanhuri, Berkah Fajar Tamtama, Nor Mohd Razif Noraini
This study investigates the relationship between Indoor Air Quality (IAQ) and air duct cleanliness, addressing the rising concern for human well-being. Airborne contaminants like dust, mold, and bacteria are identified as significant threats to IAQ, with potential health consequences. The study will also explore the several established safety and health guidelines and duct characteristics that influenced IAQ. Consequently, the primary research goal is to examine the relationship between duct cleanliness and airborne contaminants in the building environment and determine whether air duct cleaning effectively reduces these contaminants. By thoroughly reviewing studies and established standards, we examine IAQ contaminants and explore the effects of duct cleaning, along with its potential health advantages. Findings emphasize duct cleaning's potential to enhance IAQ, reduce exposure to pollutants, and its importance for building owners, facility managers, and stakeholders in safeguarding occupants' health and comfort.
{"title":"Comprehensive Review on the Relationship between Duct Cleanliness and Airborne Contaminants","authors":"Mohd Arif Rosli, Muhamad Shahril Mohd Abdullah, Azian Hariri, Amir Abdullah Muhamad Damanhuri, Berkah Fajar Tamtama, Nor Mohd Razif Noraini","doi":"10.37934/arfmts.115.2.6169","DOIUrl":"https://doi.org/10.37934/arfmts.115.2.6169","url":null,"abstract":"This study investigates the relationship between Indoor Air Quality (IAQ) and air duct cleanliness, addressing the rising concern for human well-being. Airborne contaminants like dust, mold, and bacteria are identified as significant threats to IAQ, with potential health consequences. The study will also explore the several established safety and health guidelines and duct characteristics that influenced IAQ. Consequently, the primary research goal is to examine the relationship between duct cleanliness and airborne contaminants in the building environment and determine whether air duct cleaning effectively reduces these contaminants. By thoroughly reviewing studies and established standards, we examine IAQ contaminants and explore the effects of duct cleaning, along with its potential health advantages. Findings emphasize duct cleaning's potential to enhance IAQ, reduce exposure to pollutants, and its importance for building owners, facility managers, and stakeholders in safeguarding occupants' health and comfort.","PeriodicalId":37460,"journal":{"name":"Journal of Advanced Research in Fluid Mechanics and Thermal Sciences","volume":"34 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140761994","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 : 2024-04-01DOI: 10.37934/arfmts.115.2.103112
Fitria Nur Laily, Sri Rachmania Juliastuti, Raden Darmawan
Microbial Fuel Cell (MFC) are the one of utilization of waste for renewable energy continues to be developed. According to the FAO, 32% of all food for human consumption is discarded about 1.3 billion tonnes per year. In this study, Microbial Fuel Cells used an organic source in the form of food waste that had been hydrolyzed by Aspergillus oryzae, Aspergillus aculeatus, and Candida rugosa. The results of the hydrolysis are entered into the MFC system. In the MFC system it is mixed with Sidoarjo mud and Shewanella oneidensis MR-1, then put into a Single Chamber microbial fuel cell (SC-MFC) to generate electricity. In this research, also added micronutrients (Mg2+, Ni2+, Cu2+, Ca2+, Pb2+, Co2+, Cd2+, Cr2+, and Zn2+) to increase the metabolic of Shewanella oneidensis MR-1 bacteria, so can elevate electric currents. electrons and protons are produced by microorganisms by changing organic compounds in the substrate. The results showed that the best power density was 6.652 W/m2 with BOD 89.362% and COD removal 77.273% achieved with a ratio of food waste to water of 2:1 M. Food hydrolysis is capable of hydrolyzing 40% food waste into glucose within 24 hours. The greatest percentage of glucose decreased was achieved by Cobalt micronutrient addition with 77% of glucose decreased. Therefore, MFC can be greatly enhance food waste degradation to become a carbon source in a microbial fuel cell for electricity production.
{"title":"MFC Performance with Additional Micronutrients in Food Waste Substrate","authors":"Fitria Nur Laily, Sri Rachmania Juliastuti, Raden Darmawan","doi":"10.37934/arfmts.115.2.103112","DOIUrl":"https://doi.org/10.37934/arfmts.115.2.103112","url":null,"abstract":"Microbial Fuel Cell (MFC) are the one of utilization of waste for renewable energy continues to be developed. According to the FAO, 32% of all food for human consumption is discarded about 1.3 billion tonnes per year. In this study, Microbial Fuel Cells used an organic source in the form of food waste that had been hydrolyzed by Aspergillus oryzae, Aspergillus aculeatus, and Candida rugosa. The results of the hydrolysis are entered into the MFC system. In the MFC system it is mixed with Sidoarjo mud and Shewanella oneidensis MR-1, then put into a Single Chamber microbial fuel cell (SC-MFC) to generate electricity. In this research, also added micronutrients (Mg2+, Ni2+, Cu2+, Ca2+, Pb2+, Co2+, Cd2+, Cr2+, and Zn2+) to increase the metabolic of Shewanella oneidensis MR-1 bacteria, so can elevate electric currents. electrons and protons are produced by microorganisms by changing organic compounds in the substrate. The results showed that the best power density was 6.652 W/m2 with BOD 89.362% and COD removal 77.273% achieved with a ratio of food waste to water of 2:1 M. Food hydrolysis is capable of hydrolyzing 40% food waste into glucose within 24 hours. The greatest percentage of glucose decreased was achieved by Cobalt micronutrient addition with 77% of glucose decreased. Therefore, MFC can be greatly enhance food waste degradation to become a carbon source in a microbial fuel cell for electricity production.","PeriodicalId":37460,"journal":{"name":"Journal of Advanced Research in Fluid Mechanics and Thermal Sciences","volume":"11 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140782440","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 : 2024-04-01DOI: 10.37934/arfmts.115.2.7082
Mauricio Rhenals, Armando Robledo, Jonathan Fábregas, Javier Carpintero
Fluid mechanics plays a crucial role in everyday life, enabling the selection of accessories, materials, and various components essential for a system through which fluid flows. Pressure drop stands out as one of the most relevant factors in the design of fluid flow systems. However, analytical and experimental physical methods can increase these analyses' costs and time. Hence, in this study, statistical tools are employed to carry out specific experiments supported by numerical fluid simulation, aiming to comprehend the pressure drop behavior in a fluid as it passes through a globe valve. This valve, in turn, possesses distinct operating and manufacturing characteristics. The methods employed encompass a complete factorial system of response surface as support to construct the experimental design path through computational fluid dynamics. Among the key findings, it is demonstrated that, for systems with relatively low flow rates, the valve opening percentage does not exhibit a significant relationship with fluid pressure drop. Conversely, significant effects are observed for systems with relatively high flow rates regarding the valve opening percentage and pressure drop, reaching values of up to 73% pressure drop in this study. It can be inferred that the integration of statistical experimental design techniques and computational fluid dynamics constitutes a valuable resource for studying the pressure drop of a fluid passing through a system.
{"title":"Analysis of Fluid Pressure Drop through a Globe Valve using Computational Fluid Dynamics and Statistical Techniques","authors":"Mauricio Rhenals, Armando Robledo, Jonathan Fábregas, Javier Carpintero","doi":"10.37934/arfmts.115.2.7082","DOIUrl":"https://doi.org/10.37934/arfmts.115.2.7082","url":null,"abstract":"Fluid mechanics plays a crucial role in everyday life, enabling the selection of accessories, materials, and various components essential for a system through which fluid flows. Pressure drop stands out as one of the most relevant factors in the design of fluid flow systems. However, analytical and experimental physical methods can increase these analyses' costs and time. Hence, in this study, statistical tools are employed to carry out specific experiments supported by numerical fluid simulation, aiming to comprehend the pressure drop behavior in a fluid as it passes through a globe valve. This valve, in turn, possesses distinct operating and manufacturing characteristics. The methods employed encompass a complete factorial system of response surface as support to construct the experimental design path through computational fluid dynamics. Among the key findings, it is demonstrated that, for systems with relatively low flow rates, the valve opening percentage does not exhibit a significant relationship with fluid pressure drop. Conversely, significant effects are observed for systems with relatively high flow rates regarding the valve opening percentage and pressure drop, reaching values of up to 73% pressure drop in this study. It can be inferred that the integration of statistical experimental design techniques and computational fluid dynamics constitutes a valuable resource for studying the pressure drop of a fluid passing through a system.","PeriodicalId":37460,"journal":{"name":"Journal of Advanced Research in Fluid Mechanics and Thermal Sciences","volume":"182 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140793827","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 : 2024-04-01DOI: 10.37934/arfmts.115.2.1332
Siti Nur Aisyah Azeman, Anis Zafirah Azmi, Nurul Hafizah Zainal Abidin, Nor Alwani Omar
Convective heat transfer is vital in a variety of engineering applications, including thermal management systems, electronic refrigeration, and energy conversion devices. Improving the rate of heat transfer in these systems is of the utmost significance for increasing their efficiency. This review focuses on the single and combined effects of these parameters on improving heat transmission in such systems. The heat and mass transfer of nanofluid is greatly influenced by various factors, including the intrinsic features of the nanofluid, the process used for synthesising the nanofluid, the impact of magnetic force, the concentration and size of nanoparticles, and the Reynolds number (Re). Furthermore, it is important to note that the material characteristics, thermal properties, and performance of magnetic nanofluids are significantly influenced by slight variations in the magnetic force and magnetic field gradient. Multiple research projects have reached the agreement that the inclusion of a magnetic field within magnetic nanoparticles enhances the convective heat transfer capabilities of a nanofluid, resulting in an improvement ranging from around 13% to 75%. Moreover, several applications of hybrid nanofluids in thermal systems have been introduced.
{"title":"Effect of Magnetic Flow and Convective Heat Transfer Enhancement Using Hybrid Nanofluid: A Structured Review","authors":"Siti Nur Aisyah Azeman, Anis Zafirah Azmi, Nurul Hafizah Zainal Abidin, Nor Alwani Omar","doi":"10.37934/arfmts.115.2.1332","DOIUrl":"https://doi.org/10.37934/arfmts.115.2.1332","url":null,"abstract":"Convective heat transfer is vital in a variety of engineering applications, including thermal management systems, electronic refrigeration, and energy conversion devices. Improving the rate of heat transfer in these systems is of the utmost significance for increasing their efficiency. This review focuses on the single and combined effects of these parameters on improving heat transmission in such systems. The heat and mass transfer of nanofluid is greatly influenced by various factors, including the intrinsic features of the nanofluid, the process used for synthesising the nanofluid, the impact of magnetic force, the concentration and size of nanoparticles, and the Reynolds number (Re). Furthermore, it is important to note that the material characteristics, thermal properties, and performance of magnetic nanofluids are significantly influenced by slight variations in the magnetic force and magnetic field gradient. Multiple research projects have reached the agreement that the inclusion of a magnetic field within magnetic nanoparticles enhances the convective heat transfer capabilities of a nanofluid, resulting in an improvement ranging from around 13% to 75%. Moreover, several applications of hybrid nanofluids in thermal systems have been introduced.","PeriodicalId":37460,"journal":{"name":"Journal of Advanced Research in Fluid Mechanics and Thermal Sciences","volume":"108 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140768730","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}
The introduction of electromagnetic fields in fluid dynamics in magnetohydrodynamics (MHD), particularly when those fields are vector and non-uniform, complicates its application in vortex geometry. The imperative to optimize MHD generators arises from the inherent trade-off between voltage and pressure drop in energy conversion systems, to maximize voltage output while minimizing associated pressure drop. This study focuses on optimizing vortex MHD generators by applying Response Surface Methodology (RSM), which is based on mathematical models that capture the complex relationships between factor and response variables. This method offers a comprehensive approach to obtaining the optimum solution to the objectives, voltage and pressure drop, based on fluid velocity and magnetic field strength input parameters. Numerical optimization RSM generates 11 solutions. The optimum solutions obtained are a velocity of 1.415 m/s, and magnetic field strength of 0.43 T, and the corresponding optimum output voltage and pressure drop will be 4.264 mV and 4.254 psi, respectively, with a desirability level of the selected solution is 0.770. This study suggests the RSM method shows a good measurement of R2 and RSME. Our findings contribute to the understanding of optimizing vortex MHD generators and offer insights into achieving efficient energy conversion systems of a set of optimum generator operating parameters.
{"title":"Multi-Objective Optimization of Vortex Magnetohydrodynamics (MHD) Generator using Response Surface Methodology","authors":"Arleen Natalie, Ridho Irwansyah, Budiarso, Nasruddin","doi":"10.37934/arfmts.115.2.3349","DOIUrl":"https://doi.org/10.37934/arfmts.115.2.3349","url":null,"abstract":"The introduction of electromagnetic fields in fluid dynamics in magnetohydrodynamics (MHD), particularly when those fields are vector and non-uniform, complicates its application in vortex geometry. The imperative to optimize MHD generators arises from the inherent trade-off between voltage and pressure drop in energy conversion systems, to maximize voltage output while minimizing associated pressure drop. This study focuses on optimizing vortex MHD generators by applying Response Surface Methodology (RSM), which is based on mathematical models that capture the complex relationships between factor and response variables. This method offers a comprehensive approach to obtaining the optimum solution to the objectives, voltage and pressure drop, based on fluid velocity and magnetic field strength input parameters. Numerical optimization RSM generates 11 solutions. The optimum solutions obtained are a velocity of 1.415 m/s, and magnetic field strength of 0.43 T, and the corresponding optimum output voltage and pressure drop will be 4.264 mV and 4.254 psi, respectively, with a desirability level of the selected solution is 0.770. This study suggests the RSM method shows a good measurement of R2 and RSME. Our findings contribute to the understanding of optimizing vortex MHD generators and offer insights into achieving efficient energy conversion systems of a set of optimum generator operating parameters.","PeriodicalId":37460,"journal":{"name":"Journal of Advanced Research in Fluid Mechanics and Thermal Sciences","volume":"346 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140788668","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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