{"title":"ENTROPY GENERATION OF THREE DIMENSIONAL BINGHAM NANOFLUID FLOW WITH CARBON NANOTUBES PASSING THROUGH PARALLEL PLATES","authors":"N. Vijaya, P. Nagalakshmi","doi":"10.5098/hmt.19.17","DOIUrl":"https://doi.org/10.5098/hmt.19.17","url":null,"abstract":"","PeriodicalId":46200,"journal":{"name":"Frontiers in Heat and Mass Transfer","volume":"43 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87303256","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}
{"title":"NUMERICAL INVESTIGATION OF COUPLED NATURAL CONVECTION AND SURFACE RADIATION IN A SQUARE CAVITY WITH THE LINEARLY HEATED SIDE WALL(S)","authors":"R. Prasad, S. Singh, A. Gupta","doi":"10.5098/hmt.19.16","DOIUrl":"https://doi.org/10.5098/hmt.19.16","url":null,"abstract":"","PeriodicalId":46200,"journal":{"name":"Frontiers in Heat and Mass Transfer","volume":"333 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80573575","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}
{"title":"EXERGY ANALYSIS OF A REFRIGERATION SYSTEM WITH A MINICHANNEL CONDENSER USING R134A REFRIGERANT","authors":"V. Bhatkar, Anirban Sur, A. Roy","doi":"10.5098/hmt.19.15","DOIUrl":"https://doi.org/10.5098/hmt.19.15","url":null,"abstract":"","PeriodicalId":46200,"journal":{"name":"Frontiers in Heat and Mass Transfer","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76589175","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}
Numerical analysis of liquid vapor slug flow in a vertically placed U-shaped closed capillary tube is carried out with family of hydrocarbon fluid like Acetone, Ethanol, Methanol and Pentane. A 3D computational domain has been developed for vertically placed U-shaped capillary tube sealed at both end with three small turns in evaporator section, two small and one large turn in condenser section. The diameter of vertically placed U-shaped capillary tube is taken as 2mm. The volume of fluid (VOF) approach, suitable model of K-epsilon is used to predict the behavior of liquid vapor slug flow along the wall of capillary tube. Fill ratio (FR) of 61% is used with the working fluid that occupies 61% of the total volume of tube. At the start of iteration process the evaporator and condenser temperature are set to 343 K and 298 K. The liquid, vapor slug flow inside the capillary tube and flow patterns are observed for Acetone, Ethanol, Methanol and Pentane. The contours of liquid volume fraction and wall temperature are observed along the length of tube. Alternate liquid and vapor slug formation and the complex phenomenon of evaporation and condensation process are visualized in the analysis. The aim of the numerical analysis is to find the suitable working fluid, models, simulation settings that accurately predict the phase change phenomenon and to investigate the effect of liquid vapor slug flow, changing simulation parameters on the performance of U-shaped capillary tube.
{"title":"NUMERICAL ANALYSIS TO PREDICT THE BEHAVIOR OF LIQUID VAPOR SLUG FLOW IN VERTICALLY PLACED U-SHAPED CLOSED CAPILLARY TUBE","authors":"R. D. Bhagat, S. Deshmukh","doi":"10.5098/hmt.19.14","DOIUrl":"https://doi.org/10.5098/hmt.19.14","url":null,"abstract":"Numerical analysis of liquid vapor slug flow in a vertically placed U-shaped closed capillary tube is carried out with family of hydrocarbon fluid like Acetone, Ethanol, Methanol and Pentane. A 3D computational domain has been developed for vertically placed U-shaped capillary tube sealed at both end with three small turns in evaporator section, two small and one large turn in condenser section. The diameter of vertically placed U-shaped capillary tube is taken as 2mm. The volume of fluid (VOF) approach, suitable model of K-epsilon is used to predict the behavior of liquid vapor slug flow along the wall of capillary tube. Fill ratio (FR) of 61% is used with the working fluid that occupies 61% of the total volume of tube. At the start of iteration process the evaporator and condenser temperature are set to 343 K and 298 K. The liquid, vapor slug flow inside the capillary tube and flow patterns are observed for Acetone, Ethanol, Methanol and Pentane. The contours of liquid volume fraction and wall temperature are observed along the length of tube. Alternate liquid and vapor slug formation and the complex phenomenon of evaporation and condensation process are visualized in the analysis. The aim of the numerical analysis is to find the suitable working fluid, models, simulation settings that accurately predict the phase change phenomenon and to investigate the effect of liquid vapor slug flow, changing simulation parameters on the performance of U-shaped capillary tube.","PeriodicalId":46200,"journal":{"name":"Frontiers in Heat and Mass Transfer","volume":"52 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77031448","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}
Xinghua Ju, Mingjie Zhang, Kailei Yang, Le Qin, Xiaole Yao, Qian Liu
Lithium-ion batteries used for energy storage systems will release amount of heat during operation. It will cause serious consequences of thermal runaway if not dissipate in time. In this study, a self-forming air-cooled battery rack of the energy storage system is established based on the normal battery rack for energy storage and the shape of the energy storage battery itself. The frames of the battery rack acts as air ducts, which greatly reduce the system complexity. In this paper, the heat generation model is established based on the experiment, and the four battery rack forms are studied by CFD simulation. The flow uniformity of the two-level shunt structure, the maximum temperature of the battery, the temperature difference and the overall pressure drop of the battery rack are analyzed. It was found that the self-forming battery rack in the form of Case Ⅳ has the highest flow rate and temperature uniformity due to the tapered air ducts. Case Ⅳ can also resist flow non-uniformity when increase the flow rate. The maximum temperature can be maintained at 33.8 o C at 0.5 C under the 46 g/s flowrate. Where the maximum bulk temperature difference between batteries and inside a single battery is less than 3.8 o C and 1 o C, respectively. The pressure drop is only 4.8 Pa . What’s more, Case Ⅳ achieves optimal cooling performance at a 92 g/s flow rate, under which the maximum bulk temperature is 31.8 o C with the pressure drop of 19.5 Pa.
{"title":"RESEARCH ON A NOVEL CONCEPT OF SELF-FORMING AIR COOLING BATTERY RACK","authors":"Xinghua Ju, Mingjie Zhang, Kailei Yang, Le Qin, Xiaole Yao, Qian Liu","doi":"10.5098/hmt.19.13","DOIUrl":"https://doi.org/10.5098/hmt.19.13","url":null,"abstract":"Lithium-ion batteries used for energy storage systems will release amount of heat during operation. It will cause serious consequences of thermal runaway if not dissipate in time. In this study, a self-forming air-cooled battery rack of the energy storage system is established based on the normal battery rack for energy storage and the shape of the energy storage battery itself. The frames of the battery rack acts as air ducts, which greatly reduce the system complexity. In this paper, the heat generation model is established based on the experiment, and the four battery rack forms are studied by CFD simulation. The flow uniformity of the two-level shunt structure, the maximum temperature of the battery, the temperature difference and the overall pressure drop of the battery rack are analyzed. It was found that the self-forming battery rack in the form of Case Ⅳ has the highest flow rate and temperature uniformity due to the tapered air ducts. Case Ⅳ can also resist flow non-uniformity when increase the flow rate. The maximum temperature can be maintained at 33.8 o C at 0.5 C under the 46 g/s flowrate. Where the maximum bulk temperature difference between batteries and inside a single battery is less than 3.8 o C and 1 o C, respectively. The pressure drop is only 4.8 Pa . What’s more, Case Ⅳ achieves optimal cooling performance at a 92 g/s flow rate, under which the maximum bulk temperature is 31.8 o C with the pressure drop of 19.5 Pa.","PeriodicalId":46200,"journal":{"name":"Frontiers in Heat and Mass Transfer","volume":"4 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90309494","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}
A magnetohydrodynamics (MHD) flow of fractional Maxwell fluid past an exponentially accelerated vertical plate is considered. In addition, other factors such as heat generation and chemical reaction are used in the problem. The flow model is solved using Caputo fractional derivative. Initially, the governing equations are made non-dimensional and then solved by Laplace transform. The influence of different parameters like diffusion thermo, fractional parameter, Magnetic field, chemical reaction, Prandtl number and Maxwell parameter are discussed through numerous graphs. From figures, it is observed that fluid motion decreases with increasing values of Schmidt number and chemical reaction, whereas velocity field decreases with decreasing values of diffusion thermo and heat generation.
{"title":"EFFECT OF DIFFUSION-THERMO ON MHD FLOW OF MAXWELL FLUID WITH HEAT AND MASS TRANSFER","authors":"M. Ramzan, Z. Nisa, M. Nazar","doi":"10.5098/hmt.19.12","DOIUrl":"https://doi.org/10.5098/hmt.19.12","url":null,"abstract":"A magnetohydrodynamics (MHD) flow of fractional Maxwell fluid past an exponentially accelerated vertical plate is considered. In addition, other factors such as heat generation and chemical reaction are used in the problem. The flow model is solved using Caputo fractional derivative. Initially, the governing equations are made non-dimensional and then solved by Laplace transform. The influence of different parameters like diffusion thermo, fractional parameter, Magnetic field, chemical reaction, Prandtl number and Maxwell parameter are discussed through numerous graphs. From figures, it is observed that fluid motion decreases with increasing values of Schmidt number and chemical reaction, whereas velocity field decreases with decreasing values of diffusion thermo and heat generation.","PeriodicalId":46200,"journal":{"name":"Frontiers in Heat and Mass Transfer","volume":"1520 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87819715","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}
{"title":"NUMERICAL AND EXPERIMENTAL INVESTIGATION OF NONLUBRICATED AIR SCROLL EXPANDER DERIVED FROM A REFRIGERANT SCROLL COMPRESSOR","authors":"Ramakrishna Konijeti, Aparna Kottapalli","doi":"10.5098/hmt.19.11","DOIUrl":"https://doi.org/10.5098/hmt.19.11","url":null,"abstract":"","PeriodicalId":46200,"journal":{"name":"Frontiers in Heat and Mass Transfer","volume":"55 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72812548","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}
In the present study, the use of wavy fin turbulators on the annulus body of a double pipe air heater has been numerically investigated. The inner pipe consists of hot water whereas the annular section consists of cold air whose Reynolds Number (Re) ranged from 3000-15,000. Rectangular cross-sectioned wavy fin turbulators with various curvature ratios of 2, 3, 5, and 7.5 is numerically simulated to investigate the influence of curvature effects on turbulence. Results have been compared with the bare pipe and with rectangular straight fins. It is seen that wavy fin turbulators perform better (compared to (other two) bare and rectangular straight fin) than both of them by creating turbulence effects in the flow field. Nusselt number (Nu) is increased by 256% and 51% as compared to bare and rectangular straight fin type. Parametric studies revealed that as the curvature ratio (CR) is reduced, the turbulent intensity and turbulent kinetic energy increase with better heat transfer characteristics. The highest Thermo hydraulic performance index of 4.8 is noticed for the CR of 2 at a Re of 6000 and is 34% higher than the straight rectangular fin.
{"title":"STUDY ON HEAT TRANSFER AUGMENTATION IN AN AIR HEATER USING RECTANGULAR WAVY FIN TURBULATORS","authors":"Shiva Kumar, Nitesh Kumar","doi":"10.5098/hmt.19.10","DOIUrl":"https://doi.org/10.5098/hmt.19.10","url":null,"abstract":"In the present study, the use of wavy fin turbulators on the annulus body of a double pipe air heater has been numerically investigated. The inner pipe consists of hot water whereas the annular section consists of cold air whose Reynolds Number (Re) ranged from 3000-15,000. Rectangular cross-sectioned wavy fin turbulators with various curvature ratios of 2, 3, 5, and 7.5 is numerically simulated to investigate the influence of curvature effects on turbulence. Results have been compared with the bare pipe and with rectangular straight fins. It is seen that wavy fin turbulators perform better (compared to (other two) bare and rectangular straight fin) than both of them by creating turbulence effects in the flow field. Nusselt number (Nu) is increased by 256% and 51% as compared to bare and rectangular straight fin type. Parametric studies revealed that as the curvature ratio (CR) is reduced, the turbulent intensity and turbulent kinetic energy increase with better heat transfer characteristics. The highest Thermo hydraulic performance index of 4.8 is noticed for the CR of 2 at a Re of 6000 and is 34% higher than the straight rectangular fin.","PeriodicalId":46200,"journal":{"name":"Frontiers in Heat and Mass Transfer","volume":"122 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87718582","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}
A. C. Budiman, S. Hasheminejad, S. Sudirja, A. Mitayani, S. Winoto
Streamwise development of counter-rotating vortices induced by three different types of chevron Vortex Generators (VGs) placed upstream an Electric Vehicles (EV) dummy battery module is experimentally visualized using a smoke-wire method. From the single chevron reference case, the mushroom-like vortices do not collapse until passing the module. When more chevrons are used in line, the vortices become more prominent. It can also be observed that the vortex sizes and shapes are significantly influenced by the spanwise base length of the chevron. The induced vortices from all three VGs suggest a potential heat transfer augmentation for the EV battery module application.
{"title":"VISUALIZATION OF INDUCED COUNTER-ROTATING VORTICES FOR ELECTRIC VEHICLES BATTERY MODULE THERMAL MANAGEMENT","authors":"A. C. Budiman, S. Hasheminejad, S. Sudirja, A. Mitayani, S. Winoto","doi":"10.5098/hmt.19.9","DOIUrl":"https://doi.org/10.5098/hmt.19.9","url":null,"abstract":"Streamwise development of counter-rotating vortices induced by three different types of chevron Vortex Generators (VGs) placed upstream an Electric Vehicles (EV) dummy battery module is experimentally visualized using a smoke-wire method. From the single chevron reference case, the mushroom-like vortices do not collapse until passing the module. When more chevrons are used in line, the vortices become more prominent. It can also be observed that the vortex sizes and shapes are significantly influenced by the spanwise base length of the chevron. The induced vortices from all three VGs suggest a potential heat transfer augmentation for the EV battery module application.","PeriodicalId":46200,"journal":{"name":"Frontiers in Heat and Mass Transfer","volume":"116 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73709109","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}
Perforated fin forced convection heat transfer is the primary focus of this investigation. The purpose of this research is to see if perforated pin fins can help with heat transmission in the devices. Each pin's perforation diameter and number of holes are rigorously examined. The Nusselt numbers for perforated pins are 47 percent higher than those for solid pins, according to the study, and this number raises as the number of holes increases. The pressure drop is reduced by 19% when perforated pins are used instead of solid pins. Heat transmission in a round-holed pin fin was studied using forced convection in tests. Perforations in the shape of circles were among the options available. For the sake of this investigation, a number of perforations were made. For example, all of the fins and readings have one to four perforated holes. Perforated fins can promote heat transfer because of the improved Nusselt number, increased convective heat transfer coefficient, and decreased pressure gradient provided by this model is 40% smaller and up to 85% more effective at transferring heat. As a result, eddy currents are lessened.
{"title":"THE EFFECTS OF NUSSELT, REYNOLDS NUMBER, AND PRESSURE DROP ON THE THERMAL PERFORMANCE OF PIERCED PIN FINS","authors":"Wadhah H. Al Doori","doi":"10.5098/hmt.19.8","DOIUrl":"https://doi.org/10.5098/hmt.19.8","url":null,"abstract":"Perforated fin forced convection heat transfer is the primary focus of this investigation. The purpose of this research is to see if perforated pin fins can help with heat transmission in the devices. Each pin's perforation diameter and number of holes are rigorously examined. The Nusselt numbers for perforated pins are 47 percent higher than those for solid pins, according to the study, and this number raises as the number of holes increases. The pressure drop is reduced by 19% when perforated pins are used instead of solid pins. Heat transmission in a round-holed pin fin was studied using forced convection in tests. Perforations in the shape of circles were among the options available. For the sake of this investigation, a number of perforations were made. For example, all of the fins and readings have one to four perforated holes. Perforated fins can promote heat transfer because of the improved Nusselt number, increased convective heat transfer coefficient, and decreased pressure gradient provided by this model is 40% smaller and up to 85% more effective at transferring heat. As a result, eddy currents are lessened.","PeriodicalId":46200,"journal":{"name":"Frontiers in Heat and Mass Transfer","volume":"1 6 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90368392","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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