Pub Date : 2024-07-01DOI: 10.1615/heattransres.2024053386
Xuan Gao, Yuhang Li, Yakang Xia, Haiwang Li
Spray cooling exhibits outstanding cooling performances compared to other liquid cooling techniques, which offers robust thermal management for numerous applications facing high heat flux challenges. In spray cooling, coolant droplets generated from a spray nozzle continuously impinge onto a hot surface at high flow rates. The interaction between the droplets and the surface-whether they land on a pre-existing liquid film or directly on the heated area depends on the fluid's saturation temperature and the surface's temperature. Understanding the dynamics and heat transfer during droplet impact is crucial for advancing spray cooling research. The present work summarizes the recent advancements in the study of droplet impact dynamics and heat transfer in spray cooling from two aspects. The first aspect is about the statistical analyses of droplet behaviors and liquid film conditions in spray cooling, examining their influence on cooling efficiency. The second one is regarding the droplet-surface interactions in spray cooling, ranging from single droplet to spray by increasing the complexity of droplet condition and surface condition. It includes the single droplet impacting a dry heated surface, multiple droplets impacting a dry heated surface, and droplet impacting the heated flowing film.
{"title":"A Review on Thermo-fluidic Study of Droplets Impact in Spray Cooling","authors":"Xuan Gao, Yuhang Li, Yakang Xia, Haiwang Li","doi":"10.1615/heattransres.2024053386","DOIUrl":"https://doi.org/10.1615/heattransres.2024053386","url":null,"abstract":"Spray cooling exhibits outstanding cooling performances compared to other liquid cooling techniques, which offers robust thermal management for numerous applications facing high heat flux challenges. In spray cooling, coolant droplets generated from a spray nozzle continuously impinge onto a hot surface at high flow rates. The interaction between the droplets and the surface-whether they land on a pre-existing liquid film or directly on the heated area depends on the fluid's saturation temperature and the surface's temperature. Understanding the dynamics and heat transfer during droplet impact is crucial for advancing spray cooling research. The present work summarizes the recent advancements in the study of droplet impact dynamics and heat transfer in spray cooling from two aspects. The first aspect is about the statistical analyses of droplet behaviors and liquid film conditions in spray cooling, examining their influence on cooling efficiency. The second one is regarding the droplet-surface interactions in spray cooling, ranging from single droplet to spray by increasing the complexity of droplet condition and surface condition. It includes the single droplet impacting a dry heated surface, multiple droplets impacting a dry heated surface, and droplet impacting the heated flowing film.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"30 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1615/heattransres.2024054096
Youngsuk Oh, Zhixiong Guo
In this study, machine learning-based predictions of thermal conductivity, dynamic viscosity, and specific heat of nanofluids are explored. Various types of nanofluids and parametric conditions are considered to broaden and evaluate the effectiveness of popular machine learning models, including multilayer perceptron, random forest, light gradient boosting machine, extreme gradient boosting and stacking algorithms. The performance of these prediction models is assessed using mean squared error and coefficient of determination. The influence of each input variable on model development was examined to identify key features. Information gain is introduced and calculated for determining the importance of parameters in prediction. External validation is performed with an additional unseen dataset to further assess the applicability of the selected models across different experimental data points. It was found that the stacking technique is the most accurate machine learning algorithm among those investigated. The results demonstrate that machine learning methods can provide excellent predictions of the thermophysical properties of complex nanofluids.
{"title":"Machine learning-based predictions of nanofluid thermal properties","authors":"Youngsuk Oh, Zhixiong Guo","doi":"10.1615/heattransres.2024054096","DOIUrl":"https://doi.org/10.1615/heattransres.2024054096","url":null,"abstract":"In this study, machine learning-based predictions of thermal conductivity, dynamic viscosity, and specific heat of nanofluids are explored. Various types of nanofluids and parametric conditions are considered to broaden and evaluate the effectiveness of popular machine learning models, including multilayer perceptron, random forest, light gradient boosting machine, extreme gradient boosting and stacking algorithms. The performance of these prediction models is assessed using mean squared error and coefficient of determination. The influence of each input variable on model development was examined to identify key features. Information gain is introduced and calculated for determining the importance of parameters in prediction. External validation is performed with an additional unseen dataset to further assess the applicability of the selected models across different experimental data points. It was found that the stacking technique is the most accurate machine learning algorithm among those investigated. The results demonstrate that machine learning methods can provide excellent predictions of the thermophysical properties of complex nanofluids.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"3 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The current work aims numerically to investigate and analyze the entropy generation and thermal efficiency of 〖Fe〗_3 O_4/water nanofluids flowing through a heat exchanger considering multiple identical magnetic sources. The simulated domain corresponds to a minichannel heated from below at a constant temperature, while its upper wall is adiabatic. Numerical simulations were carried out using the finite volume method (VFM). To determine the new thermophysical properties of the magnetic nanofluid, the monophasic approach was adopted. The obtained results are presented as the Nusselt number, streamlines, isotherms and generated entropy with other relevant parameters, namely, the magnetic field strength, number of magnet pairs, number of Reynolds numbers and volumetric fraction of the nanoparticles. The investigation revealed that these parameters significantly influence the heat transfer mechanism. Selecting these parameters carefully is crucial for achieving enhanced generation of entropy and, consequently, desirable improvement in heat transfer
{"title":"Heat and fluid flow characteristics of ferrofluids circulating in a heat exchanger with a magnetic vortex generator","authors":"Laila Boutas, Mbarek Marzougui, Jamil Zinoubi, Soufien GANNOUNI","doi":"10.1615/heattransres.2024052231","DOIUrl":"https://doi.org/10.1615/heattransres.2024052231","url":null,"abstract":"The current work aims numerically to investigate and analyze the entropy generation and thermal efficiency of 〖Fe〗_3 O_4/water nanofluids flowing through a heat exchanger considering multiple identical magnetic sources. The simulated domain corresponds to a minichannel heated from below at a constant temperature, while its upper wall is adiabatic. Numerical simulations were carried out using the finite volume method (VFM). To determine the new thermophysical properties of the magnetic nanofluid, the monophasic approach was adopted. The obtained results are presented as the Nusselt number, streamlines, isotherms and generated entropy with other relevant parameters, namely, the magnetic field strength, number of magnet pairs, number of Reynolds numbers and volumetric fraction of the nanoparticles. The investigation revealed that these parameters significantly influence the heat transfer mechanism. Selecting these parameters carefully is crucial for achieving enhanced generation of entropy and, consequently, desirable improvement in heat transfer","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"39 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1615/heattransres.2024052576
Yeliz Alnak
In this study, heat transfer performance and fluid flow properties for cross-circular grooved triangular ducts having different location angles and heights of the triangular baffles are numerically searched. The program of Ansys-Fluent is applied to find out the equations of energy and Navier Stokes by employing the turbulence model of k-ε in computational calculations. While the temperature of the inlet of air working fluid is 293 K, values of the wall surface temperature of the lower circular grooved channel are taken as constant 373 K. Triangular baffles have different angles of 30o, 60o and 90o and heights of 0.25H, 0.5H and 0.75H. The range of the Reynolds number employed in this study is 1000-6000. Numerical results agreed with a 3.53% deviation according to empirical work that existed in technical literature. The attained outcomes are presented as mean Nu number, fluid temperature, turbulence kinetic energy, pressure and Performance Evaluation Criterion (PEC) number variations for each triangle baffle angle and height. Distributions of the contour of the temperature, velocity, turbulence kinetic energy and vector of velocity are also evaluated for distinct Re numbers and triangle baffle arrangements. For Re=3000, the Num number in the channel with a 90o baffle angle and 0.75H height is 136.73% higher than that in the channel with 0.25H height, and in the 0.25H baffle height channel, the PEC number is 91.91% higher in the 30o baffle angle condition than in the 90o.
{"title":"Research of Triangular Baffle Placement Effect on the Heat Transfer and Flow Features in Cross-Triangular Grooved Triangular Channels","authors":"Yeliz Alnak","doi":"10.1615/heattransres.2024052576","DOIUrl":"https://doi.org/10.1615/heattransres.2024052576","url":null,"abstract":"In this study, heat transfer performance and fluid flow properties for cross-circular grooved triangular ducts having different location angles and heights of the triangular baffles are numerically searched. The program of Ansys-Fluent is applied to find out the equations of energy and Navier Stokes by employing the turbulence model of k-ε in computational calculations. While the temperature of the inlet of air working fluid is 293 K, values of the wall surface temperature of the lower circular grooved channel are taken as constant 373 K. Triangular baffles have different angles of 30o, 60o and 90o and heights of 0.25H, 0.5H and 0.75H. The range of the Reynolds number employed in this study is 1000-6000. Numerical results agreed with a 3.53% deviation according to empirical work that existed in technical literature. The attained outcomes are presented as mean Nu number, fluid temperature, turbulence kinetic energy, pressure and Performance Evaluation Criterion (PEC) number variations for each triangle baffle angle and height. Distributions of the contour of the temperature, velocity, turbulence kinetic energy and vector of velocity are also evaluated for distinct Re numbers and triangle baffle arrangements. For Re=3000, the Num number in the channel with a 90o baffle angle and 0.75H height is 136.73% higher than that in the channel with 0.25H height, and in the 0.25H baffle height channel, the PEC number is 91.91% higher in the 30o baffle angle condition than in the 90o.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"47 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1615/heattransres.2024053359
Haluk Keleş, Yücel Özmen
In this study, the effects of heat transfer in turbulent flow fields of impinging slot jet confined by inclined plates were investigated experimentally. Temperature distributions on the impingement plates were obtained with thermal camera. Temperature measurements were carried out on the impingement plate in four different impinging slot jet flow setups confined by plates with inclination angles of θ = 0°, 15°, 30° and 45°, with an inter-plate spacing of 0.5 ≤ H/W ≤ 6 and a Reynolds number range of 10000 ≤ Re ≤ 30000. The effects of confinement plate inclination angle, intervals among plates and Reynolds number on the Nusselt distributions of the impingement plates were examined. It was observed that Nusselt values increased with increasing Reynolds number and decreased with increasing intervals among plates. There are secondary top points in the Nusselt distributions on the impingement plate for low inclined confinement plates (θ=0° and θ=15°) and low inter-plate spacings (H/W=0. 5 and H/W=1), while there is an increase in the Nusselt numbers at the ends of the impingement plate for high inclined confinement plates (θ=30° and θ=45°) and low inter-plate spacings (H/W=0.5 and H/W=1).
{"title":"Experimental study of heat transfer effects due to impinging slot jets confined by inclined plates","authors":"Haluk Keleş, Yücel Özmen","doi":"10.1615/heattransres.2024053359","DOIUrl":"https://doi.org/10.1615/heattransres.2024053359","url":null,"abstract":"In this study, the effects of heat transfer in turbulent flow fields of impinging slot jet confined by inclined plates were investigated experimentally. Temperature distributions on the impingement plates were obtained with thermal camera. Temperature measurements were carried out on the impingement plate in four different impinging slot jet flow setups confined by plates with inclination angles of θ = 0°, 15°, 30° and 45°, with an inter-plate spacing of 0.5 ≤ H/W ≤ 6 and a Reynolds number range of 10000 ≤ Re ≤ 30000. The effects of confinement plate inclination angle, intervals among plates and Reynolds number on the Nusselt distributions of the impingement plates were examined. It was observed that Nusselt values increased with increasing Reynolds number and decreased with increasing intervals among plates. There are secondary top points in the Nusselt distributions on the impingement plate for low inclined confinement plates (θ=0° and θ=15°) and low inter-plate spacings (H/W=0. 5 and H/W=1), while there is an increase in the Nusselt numbers at the ends of the impingement plate for high inclined confinement plates (θ=30° and θ=45°) and low inter-plate spacings (H/W=0.5 and H/W=1).","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"163 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The influence of filling ratio and cellulose nanofiber (CNF) nanofluid concentration on the total thermal resistance and the startup of a copper miniature two-phase closed thermosyphon (TPCT) at various heat loads are investigated experimentally in this study. Length of the device is 340 mm with inner diameter of 10 mm and 1 mm of thickness. The working fluids are deionized water (DI) and CNF suspensions with 0.5, 1 and 2 vol. % and filling ratios were set to 25, 50 and 75%. Heat load varied from 20 W to 80 W with increment of 10 W. Cooling system adopted the forced air convection. Total thermal resistance of the TPCT was obtained using the recorded data of wall temperature distribution at the steady state of each experiment. Addition of CNF with 1 vol. % to DI at filling ratio of 75% reduced the evaporator wall temperature by 40% and 23%, also it reduced the total thermal resistance by 58.78% and 33.65% at 20 and 80W, respectively. Moreover, it shortened the startup duration by 33% and reduced its temperature by 42%. This paper contains important findings that proves that CNF enhanced the thermal performance of the TPCT when applying an appropriate concentration and filling ratio.
{"title":"Impact of filling ratio and cellulose nanofiber nanofluid on the total thermal resistance and the startup of a miniature thermosyphon","authors":"Maroua Mekcem, Mahieddine Berkani, Muhittin Bilgili","doi":"10.1615/heattransres.2024051883","DOIUrl":"https://doi.org/10.1615/heattransres.2024051883","url":null,"abstract":"The influence of filling ratio and cellulose nanofiber (CNF) nanofluid concentration on the total thermal resistance and the startup of a copper miniature two-phase closed thermosyphon (TPCT) at various heat loads are investigated experimentally in this study. Length of the device is 340 mm with inner diameter of 10 mm and 1 mm of thickness. The working fluids are deionized water (DI) and CNF suspensions with 0.5, 1 and 2 vol. % and filling ratios were set to 25, 50 and 75%. Heat load varied from 20 W to 80 W with increment of 10 W. Cooling system adopted the forced air convection. Total thermal resistance of the TPCT was obtained using the recorded data of wall temperature distribution at the steady state of each experiment. Addition of CNF with 1 vol. % to DI at filling ratio of 75% reduced the evaporator wall temperature by 40% and 23%, also it reduced the total thermal resistance by 58.78% and 33.65% at 20 and 80W, respectively. Moreover, it shortened the startup duration by 33% and reduced its temperature by 42%. This paper contains important findings that proves that CNF enhanced the thermal performance of the TPCT when applying an appropriate concentration and filling ratio.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"10 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1615/heattransres.2024051103
Alberto Maria Gambelli, Federico Rossi, Giovanni Gigliotti
Carbon dioxide hydrates were formed and dissociated in a lab-scale apparatus, filled with demineralised water and porous sediments. Two different porous media were tested; the first consists of glass beads, commonly used to reproduce marine environments during lab-scale hydrate formation experiments. Natural basaltic sand, typical of the Icelandic margins, was chosen as second sediment. The role played by the two sediments, was analysed both during the hydrate formation and dissociation processes and the results were compared among each other. In particular, the pressure – temperature values measured during the dissociation phase, were compared with the phase boundary equilibrium conditions for pure carbon dioxide hydrates, carried out in absence of any porous sediment, collected from the scientific literature.
{"title":"Formation and dissociation of CO2 hydrates within a natural basaltic-based porous medium from Icelandic margins.","authors":"Alberto Maria Gambelli, Federico Rossi, Giovanni Gigliotti","doi":"10.1615/heattransres.2024051103","DOIUrl":"https://doi.org/10.1615/heattransres.2024051103","url":null,"abstract":"Carbon dioxide hydrates were formed and dissociated in a lab-scale apparatus, filled with demineralised water and porous sediments. Two different porous media were tested; the first consists of glass beads, commonly used to reproduce marine environments during lab-scale hydrate formation experiments. Natural basaltic sand, typical of the Icelandic margins, was chosen as second sediment. The role played by the two sediments, was analysed both during the hydrate formation and dissociation processes and the results were compared among each other. In particular, the pressure – temperature values measured during the dissociation phase, were compared with the phase boundary equilibrium conditions for pure carbon dioxide hydrates, carried out in absence of any porous sediment, collected from the scientific literature.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"51 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141258724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1615/heattransres.2024053867
Abdelmounaim Dadda, Abdelghani Koukouch, Mohamed Asbik, Ahmed Haddou
The persistent advancement of miniaturized electronic devices and their increased performance exacerbates the challenges concerning efficient heat transfer. This study explores innovative configurations of parallel plate fin heat sink for MOSFET cooling, combining experimental validation and numerical simulations using the ANSYS Fluent solver. A heat sink, denoted as HS1, featuring seven parallel plate fins of length L, serves as the subject of both experimental and numerical analysis. Five alternative configurations designated HS2 to HS6, maintain the overall length of HS1 whilst examining different segmentations of the middle fins. HS2, HS3, and HS4 are segmented with lengths L/3, L/4, and L/7 respectively. Introducing staggered fins, HS5 and HS6, segmented with L/7, generates translations of L/14 and L/28, respectively. Staggered fins are positioned across all proposed heat sinks at S/2 (S is the fins spacing). Analysis of combined mass flowrate and power losses on HS1 reveals distinct trends in thermal resistance and maximum junction temperatures with varying mass flowrates. The heat sink configurations exhibit a significant reduction in thermal resistance compared to HS1. The exploration of the thermo-fluidic characteristics of each configuration unveils the intricate fluid dynamics and heat transfer phenomena occurring within the heat sinks. These configurations aim to minimize the thermal resistance between the MOSFETs' junction and the ambient, effectively reducing operational temperatures. Results also demonstrate significant improvements in heat dissipation efficiency, with the best configuration showcasing a reduction in thermal resistance up to 25.37%.
{"title":"Numerical Investigations of Thermo-Fluidic Characteristics in Innovative Parallel Plate Fin Heat Sink Design Subjected to Parallel Flow: Exploring the Staggering Effect","authors":"Abdelmounaim Dadda, Abdelghani Koukouch, Mohamed Asbik, Ahmed Haddou","doi":"10.1615/heattransres.2024053867","DOIUrl":"https://doi.org/10.1615/heattransres.2024053867","url":null,"abstract":"The persistent advancement of miniaturized electronic devices and their increased performance exacerbates the challenges concerning efficient heat transfer. This study explores innovative configurations of parallel plate fin heat sink for MOSFET cooling, combining experimental validation and numerical simulations using the ANSYS Fluent solver. A heat sink, denoted as HS1, featuring seven parallel plate fins of length L, serves as the subject of both experimental and numerical analysis. Five alternative configurations designated HS2 to HS6, maintain the overall length of HS1 whilst examining different segmentations of the middle fins. HS2, HS3, and HS4 are segmented with lengths L/3, L/4, and L/7 respectively. Introducing staggered fins, HS5 and HS6, segmented with L/7, generates translations of L/14 and L/28, respectively. Staggered fins are positioned across all proposed heat sinks at S/2 (S is the fins spacing). Analysis of combined mass flowrate and power losses on HS1 reveals distinct trends in thermal resistance and maximum junction temperatures with varying mass flowrates. The heat sink configurations exhibit a significant reduction in thermal resistance compared to HS1. The exploration of the thermo-fluidic characteristics of each configuration unveils the intricate fluid dynamics and heat transfer phenomena occurring within the heat sinks. These configurations aim to minimize the thermal resistance between the MOSFETs' junction and the ambient, effectively reducing operational temperatures. Results also demonstrate significant improvements in heat dissipation efficiency, with the best configuration showcasing a reduction in thermal resistance up to 25.37%.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"157 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1615/heattransres.2024052945
RIDVAN YAKUT
In recent years, the size of electronic equipment has become smaller, while the increased processing capacity has led to progressively elevated in the heat flux. As a result of this, the performance of this equipment decreases, and their service times decrease. Although traditional cooling methods are insufficient to remove the surface's heat, new cooling techniques such as electrohydrodynamic spray (EHD-spray) cooling shows promise in guaranteeing these systems operate in the intended conditions. EHD-spray, also known as electrospray, is an atomization method that provides equal and homogeneous droplets. Although EHD has been used in many studies in the literature, its use in heat transfer has only recently become an important research area. Studies on EHD-spray, which has important advantages such as requiring a very small amount of fluid and low energy, are limited, and there are almost no studies using finned heat sinks. In the study carried out, unique design heat sinks produced with Selective Laser Melting (SLM) method were optimized with Respond Surface Method (RSM) Box-Behnken Design (BBD) management, one of the most effective design methods. In the study where heat sink surface area (HSSA), fluid composition ratio (FCR) and flow rate (FR) were used as variable parameters, the highest heat transfer coefficient (HTC) was found for 100% distilled water at a 17 ml/h flow rate, and the heat sink had the lowest surface area. The results show that EHD-spray is promising for high heat flux systems cooling.
{"title":"Response surface methodology-based novel lattice heat sink optimization for electrohydrodynamic (EHD) spray cooling","authors":"RIDVAN YAKUT","doi":"10.1615/heattransres.2024052945","DOIUrl":"https://doi.org/10.1615/heattransres.2024052945","url":null,"abstract":"In recent years, the size of electronic equipment has become smaller, while the increased processing capacity has led to progressively elevated in the heat flux. As a result of this, the performance of this equipment decreases, and their service times decrease. Although traditional cooling methods are insufficient to remove the surface's heat, new cooling techniques such as electrohydrodynamic spray (EHD-spray) cooling shows promise in guaranteeing these systems operate in the intended conditions. EHD-spray, also known as electrospray, is an atomization method that provides equal and homogeneous droplets. Although EHD has been used in many studies in the literature, its use in heat transfer has only recently become an important research area. Studies on EHD-spray, which has important advantages such as requiring a very small amount of fluid and low energy, are limited, and there are almost no studies using finned heat sinks. In the study carried out, unique design heat sinks produced with Selective Laser Melting (SLM) method were optimized with Respond Surface Method (RSM) Box-Behnken Design (BBD) management, one of the most effective design methods. In the study where heat sink surface area (HSSA), fluid composition ratio (FCR) and flow rate (FR) were used as variable parameters, the highest heat transfer coefficient (HTC) was found for 100% distilled water at a 17 ml/h flow rate, and the heat sink had the lowest surface area. The results show that EHD-spray is promising for high heat flux systems cooling.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"17 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1615/heattransres.2024053138
Jiaqi Wang, Jiaxing Liu, Haoqi Wei
The phase equilibrium of CO2 hydrates on various types of porous media is studied experimentally and modeled. The model lies in the consideration of different surface properties of the media. The experiments are conducted under controlled conditions to measure the hydrate formation conditions. The proposed model is based on the Chen-Guo theory and incorporate the surface property parameters for each type of porous media. The model’s predictions are validated by comparing them to experimental data, and it is found to fit well. Furthermore, the accuracy of model is compared with other existing models, and it is observed to have higher precision. The study contributes to a better understanding of CO2 hydrate formation on different porous media and provides a reliable model for predicting phase equilibrium conditions in such systems.
{"title":"EXPERIMENTAL STUDY AND THERMODYNAMIC SIMULATION OF CO2 HYDRATE PHASE EQUILIBRIUM CONDITIONS IN POROUS MEDIA","authors":"Jiaqi Wang, Jiaxing Liu, Haoqi Wei","doi":"10.1615/heattransres.2024053138","DOIUrl":"https://doi.org/10.1615/heattransres.2024053138","url":null,"abstract":"The phase equilibrium of CO2 hydrates on various types of porous media is studied experimentally and modeled. The model lies in the consideration of different surface properties of the media. The experiments are conducted under controlled conditions to measure the hydrate formation conditions. The proposed model is based on the Chen-Guo theory and incorporate the surface property parameters for each type of porous media. The model’s predictions are validated by comparing them to experimental data, and it is found to fit well. Furthermore, the accuracy of model is compared with other existing models, and it is observed to have higher precision. The study contributes to a better understanding of CO2 hydrate formation on different porous media and provides a reliable model for predicting phase equilibrium conditions in such systems.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"23 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141166582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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