Pub Date : 2020-12-21DOI: 10.26678/abcm.encit2020.cit20-0041
R. Turmina, C. Altafini, Carlos Alberto Costa, Giovani Dambros Telli, J. S. Rosa
The increase in greenhouse gas emissions and our dependence on fossil fuels have motivated researchers to seek the use of renewable fuels in internal combustion engines, which can be produced locally and have clean combustion. The blending method in diesel engines has been recognized as an effective alternative to partially or totally replace the use of diesel fuel. In this regard, this paper studied the operation of a small engine-generator set in mono-fuel mode (diesel fuel - DO) and in dual-fuel mode using hydrous ethanol (HET) and castor oil (OM) blends, indicating a total replacement of diesel fuel. Efficiency, power, specific fuel consumption and gaseous emissions were assessed in a single cylinder diesel cycle engine. The percentages in volume of the HET-OM samples were: 75% - 25%, 70% - 30%, 60% - 40%, and 50% - 50%. The exhaust gas temperature decreased with the mixtures. Carbon monoxide emission decreased 57%, carbon dioxide decreased 9.8%, and nitrogen oxides reduced 19%. It was also observed that the percentage of smoke opacity tends to decrease close to zero with addition of ethanol. Hydrocarbon emissions increased with rising of the OM concentration and the same for the specific fuel consumptions, which was 25.4% higher than diesel fuel. The best fuel conversion efficiency was achieved with the blend HET75-OM25, being 9% higher compared to diesel fuel operation. Power on diesel fuel operation showed a better result keeping stable, with the increase of the compression ratio and the delay of the start of injection. In general, the results confirmed that the performance is comparable to that of diesel fuel, indicating that renewable fuels appear as an alternative for the reduction of the environmental impacts and the reduction of fossil fuels consumption.
{"title":"SMALL ENGINE-GENERATOR SET OPERATING ON DUAL-FUEL MODE WITH ETHANOL – CASTOR OIL BLENDS","authors":"R. Turmina, C. Altafini, Carlos Alberto Costa, Giovani Dambros Telli, J. S. Rosa","doi":"10.26678/abcm.encit2020.cit20-0041","DOIUrl":"https://doi.org/10.26678/abcm.encit2020.cit20-0041","url":null,"abstract":"The increase in greenhouse gas emissions and our dependence on fossil fuels have motivated researchers to seek the use of renewable fuels in internal combustion engines, which can be produced locally and have clean combustion. The blending method in diesel engines has been recognized as an effective alternative to partially or totally replace the use of diesel fuel. In this regard, this paper studied the operation of a small engine-generator set in mono-fuel mode (diesel fuel - DO) and in dual-fuel mode using hydrous ethanol (HET) and castor oil (OM) blends, indicating a total replacement of diesel fuel. Efficiency, power, specific fuel consumption and gaseous emissions were assessed in a single cylinder diesel cycle engine. The percentages in volume of the HET-OM samples were: 75% - 25%, 70% - 30%, 60% - 40%, and 50% - 50%. The exhaust gas temperature decreased with the mixtures. Carbon monoxide emission decreased 57%, carbon dioxide decreased 9.8%, and nitrogen oxides reduced 19%. It was also observed that the percentage of smoke opacity tends to decrease close to zero with addition of ethanol. Hydrocarbon emissions increased with rising of the OM concentration and the same for the specific fuel consumptions, which was 25.4% higher than diesel fuel. The best fuel conversion efficiency was achieved with the blend HET75-OM25, being 9% higher compared to diesel fuel operation. Power on diesel fuel operation showed a better result keeping stable, with the increase of the compression ratio and the delay of the start of injection. In general, the results confirmed that the performance is comparable to that of diesel fuel, indicating that renewable fuels appear as an alternative for the reduction of the environmental impacts and the reduction of fossil fuels consumption.","PeriodicalId":106768,"journal":{"name":"Revista de Engenharia Térmica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121901337","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 : 2020-12-21DOI: 10.26678/abcm.encit2020.cit20-0612
G. P. D. Sousa, K. C. Gomes, Wanderley F. A. Junior, R. N. C. Duarte
Titanium is considered the fourth most widely used material in industry worldwide. Titanium minerals are currently being applied in various branches of industry, mainly in the field of pigmentation. Ilmenite (FeTiO3) is an iron and titanium oxide of more common and abundant occurrence, with theoretical composition of Fe (36.8%), Ti (31.6%) and O (31.6%). Having regard to the potential of titanium minerals and the abundance of ilmenite, together with the importance of validating direct applications of this ore, since the processing of titanium is still complex and expensive, it is necessary to study this mineral and the knowledge of its main characteristics. This work brings thermal, chemical and mineralogical characterizations of ilmenite, in order to know the potential of application of this ore as a solar absorbing material. The characterization techniques used were: X-ray diffraction (XRD) and Rietveld refinement for phase quantification, X-ray fluorescence (XRF), optical spectroscopy in the middle infrared region with Fourier Transformation by Transmittance (FTIR) and thermogravimetric thermal analysis (TGA). The analyzed sample obtained X-ray diffractogram, ilmenite (80.6%) and rutile (19.4%) as significant phases, corroborating the FRX results that indicated greater presence of Fe and titanium oxide in the ilmenite chemical composition under study. The TGA, DTA and DSC analyses indicated good thermal stability of the material in medium and high temperatures. The integration of the obtained data shows that the application of this ore as a precursor material of absorber films for selective purposes is considerable.
{"title":"POTENTIAL OF ILMENITE AS A SOLAR ABSORBER","authors":"G. P. D. Sousa, K. C. Gomes, Wanderley F. A. Junior, R. N. C. Duarte","doi":"10.26678/abcm.encit2020.cit20-0612","DOIUrl":"https://doi.org/10.26678/abcm.encit2020.cit20-0612","url":null,"abstract":"Titanium is considered the fourth most widely used material in industry worldwide. Titanium minerals are currently being applied in various branches of industry, mainly in the field of pigmentation. Ilmenite (FeTiO3) is an iron and titanium oxide of more common and abundant occurrence, with theoretical composition of Fe (36.8%), Ti (31.6%) and O (31.6%). Having regard to the potential of titanium minerals and the abundance of ilmenite, together with the importance of validating direct applications of this ore, since the processing of titanium is still complex and expensive, it is necessary to study this mineral and the knowledge of its main characteristics. This work brings thermal, chemical and mineralogical characterizations of ilmenite, in order to know the potential of application of this ore as a solar absorbing material. The characterization techniques used were: X-ray diffraction (XRD) and Rietveld refinement for phase quantification, X-ray fluorescence (XRF), optical spectroscopy in the middle infrared region with Fourier Transformation by Transmittance (FTIR) and thermogravimetric thermal analysis (TGA). The analyzed sample obtained X-ray diffractogram, ilmenite (80.6%) and rutile (19.4%) as significant phases, corroborating the FRX results that indicated greater presence of Fe and titanium oxide in the ilmenite chemical composition under study. The TGA, DTA and DSC analyses indicated good thermal stability of the material in medium and high temperatures. The integration of the obtained data shows that the application of this ore as a precursor material of absorber films for selective purposes is considerable.","PeriodicalId":106768,"journal":{"name":"Revista de Engenharia Térmica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133274834","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 : 2020-12-21DOI: 10.5380/reterm.v19i2.78625
N. Araújo, F. Sousa, F. B. Costa
Over the years, the contribution of photovoltaic energy to an eco-friendly world is continually increasing. Photovoltaic (PV) cells are commonly modelled as circuits, so finding the appropriate circuit model parameters of PV cells is crucial for performance evaluation, control, efficiency computations and maximum power point tracking of solar PV systems. The problem of finding circuit model of solar PV cells is referred to as “PV cell equivalent model problem”. In this paper, the existing research works on PV cell model parameter estimation problem are classified according to error quali-quantitative analysis, number of parameters, translation equations and PV technology. The existent models were discussed pointing out its different levels of approximation. A qualitative comparative ranking was made and four models were found to be the best ones for simulating PV cells. Besides, based on the conducted review, some recommendations for future research are provided.
{"title":"EQUIVALENT MODELS FOR PHOTOVOLTAIC CELL – A REVIEW","authors":"N. Araújo, F. Sousa, F. B. Costa","doi":"10.5380/reterm.v19i2.78625","DOIUrl":"https://doi.org/10.5380/reterm.v19i2.78625","url":null,"abstract":"Over the years, the contribution of photovoltaic energy to an eco-friendly world is continually increasing. Photovoltaic (PV) cells are commonly modelled as circuits, so finding the appropriate circuit model parameters of PV cells is crucial for performance evaluation, control, efficiency computations and maximum power point tracking of solar PV systems. The problem of finding circuit model of solar PV cells is referred to as “PV cell equivalent model problem”. In this paper, the existing research works on PV cell model parameter estimation problem are classified according to error quali-quantitative analysis, number of parameters, translation equations and PV technology. The existent models were discussed pointing out its different levels of approximation. A qualitative comparative ranking was made and four models were found to be the best ones for simulating PV cells. Besides, based on the conducted review, some recommendations for future research are provided.","PeriodicalId":106768,"journal":{"name":"Revista de Engenharia Térmica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115023042","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 : 2020-12-21DOI: 10.26678/abcm.encit2020.cit20-0559
Guilherme Lacerda, M. Curi
Thermal insulation is an important area, not restricted to mechanical engineering, but widely studied in environmentalissues, such as global warming and, above all, energy-saving, since controlling the heat flux on microprocessorsthrough temperature control on components in space applications. This work focuses on controlling the temperature incomponents that could not lose or gain so much heat in space, especiallywhen the overall safety of sending satellites onspecific missions is required. To ensure that, Multilayer Insulation (MLI) is used. With fluid mechanics and radiation-conductionheat transfer theory, it was possible to calculate the transient and stationary temperature field and heat flux inMLI. The boundary temperatures are specified at 300K and 4K. The results, from solving the resulting discretized ODE,simulated with fsolve and odeintScipy subroutines in Python, able to solve the equations numerically, were shown. Thedata given by the simulation was able to indicate the impacts of varying the layer density, emissivity of screen, the distancebetween screens and the perforation coefficient in stationary and transient approaches. A way to simulate the performanceof MLI numerically was presented. Modifying emissivity (e) showed variations higher than in the perforation coefficient(ξ). Layer density controls the distance between layers (d ), changing the conduction heat transfer. In the transient casesimulation, it was possible to notice that varying parameters impact in time to reach steady-state and final temperature.
{"title":"HEAT TRANSFER INVESTIGATION FOR A MULTILAYER INSULATION SYSTEM VIA RADIATIVE-CONDUCTIVE APPROACH UNDER LOW TEMPERATURE CONDITIONS IN SPACE","authors":"Guilherme Lacerda, M. Curi","doi":"10.26678/abcm.encit2020.cit20-0559","DOIUrl":"https://doi.org/10.26678/abcm.encit2020.cit20-0559","url":null,"abstract":"Thermal insulation is an important area, not restricted to mechanical engineering, but widely studied in environmentalissues, such as global warming and, above all, energy-saving, since controlling the heat flux on microprocessorsthrough temperature control on components in space applications. This work focuses on controlling the temperature incomponents that could not lose or gain so much heat in space, especiallywhen the overall safety of sending satellites onspecific missions is required. To ensure that, Multilayer Insulation (MLI) is used. With fluid mechanics and radiation-conductionheat transfer theory, it was possible to calculate the transient and stationary temperature field and heat flux inMLI. The boundary temperatures are specified at 300K and 4K. The results, from solving the resulting discretized ODE,simulated with fsolve and odeintScipy subroutines in Python, able to solve the equations numerically, were shown. Thedata given by the simulation was able to indicate the impacts of varying the layer density, emissivity of screen, the distancebetween screens and the perforation coefficient in stationary and transient approaches. A way to simulate the performanceof MLI numerically was presented. Modifying emissivity (e) showed variations higher than in the perforation coefficient(ξ). Layer density controls the distance between layers (d ), changing the conduction heat transfer. In the transient casesimulation, it was possible to notice that varying parameters impact in time to reach steady-state and final temperature.","PeriodicalId":106768,"journal":{"name":"Revista de Engenharia Térmica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129691874","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 : 2020-09-09DOI: 10.26678/ABCM.ENCIT2018.CIT18-0097
G. Oliveira, sidney ribeiro, G. Guimarães
The inverse problem in conducting heat is related to the determination of the boundary condition, rate of heat generation, or thermophysical properties, using temperature measurements at one or more positions of the solid. The inverse problem in conducting heat is mathematically one of the ill-posed problems, because its solution extremely sensitive to measurement errors. For a well-placed problem the following conditions must be satisfied: the solution must exist, it must be unique and must be stable on small changes of the input data. The objective of the work is to estimate the heat flux generated at the tool-chip-chip interface in a manufacturing process. The term "estimation" is used because in the temperature measurements, errors are always present and these affect the accuracy of the calculation of the heat flow.
{"title":"INVERSE PROBLEM OF A ONE-DIMENSIONAL MODEL IN MULTILAYER HEAT CONDUCTION","authors":"G. Oliveira, sidney ribeiro, G. Guimarães","doi":"10.26678/ABCM.ENCIT2018.CIT18-0097","DOIUrl":"https://doi.org/10.26678/ABCM.ENCIT2018.CIT18-0097","url":null,"abstract":"The inverse problem in conducting heat is related to the determination of the boundary condition, rate of heat generation, or thermophysical properties, using temperature measurements at one or more positions of the solid. The inverse problem in conducting heat is mathematically one of the ill-posed problems, because its solution extremely sensitive to measurement errors. For a well-placed problem the following conditions must be satisfied: the solution must exist, it must be unique and must be stable on small changes of the input data. The objective of the work is to estimate the heat flux generated at the tool-chip-chip interface in a manufacturing process. The term \"estimation\" is used because in the temperature measurements, errors are always present and these affect the accuracy of the calculation of the heat flow.","PeriodicalId":106768,"journal":{"name":"Revista de Engenharia Térmica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115122849","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 : 2020-05-29DOI: 10.1101/2020.05.29.20116723
A. Diógenes, D. Tedesco
An epidemic curve is a graphic depiction of the number of outbreak cases by date of illness onset, ordinarily constructed after the disease outbreak is over. However, a good estimate of the epidemic curve early in an outbreak would be invaluable to health care officials. On the other hand, from the end of February, the SARS-CoV-2 epidemic in Brazil seems to not following the Europe, or in particular, Italy or Spain. Even if less tests have been applied, there are less deaths occurring in Brazil than in both cited countries. However, due to the few applied tests, there is no certain planning on the real number of active cases. To estimate the number of future cases, epidemiologists make an educated guess as to how many people might become affected. We have proposed a simple fitting model using a simulated annealing technique, testing it with the South Korea data. We have tested and discussed the uncertainties of the model. We also have analyzed the trends in the confirmed cases using this model for the five most affected countries plus Brazil along several epidemic weeks.
{"title":"A simple Stochastic model for the SARS-CoV-2 Epidemic curve","authors":"A. Diógenes, D. Tedesco","doi":"10.1101/2020.05.29.20116723","DOIUrl":"https://doi.org/10.1101/2020.05.29.20116723","url":null,"abstract":"An epidemic curve is a graphic depiction of the number of outbreak cases by date of illness onset, ordinarily constructed after the disease outbreak is over. However, a good estimate of the epidemic curve early in an outbreak would be invaluable to health care officials. On the other hand, from the end of February, the SARS-CoV-2 epidemic in Brazil seems to not following the Europe, or in particular, Italy or Spain. Even if less tests have been applied, there are less deaths occurring in Brazil than in both cited countries. However, due to the few applied tests, there is no certain planning on the real number of active cases. To estimate the number of future cases, epidemiologists make an educated guess as to how many people might become affected. We have proposed a simple fitting model using a simulated annealing technique, testing it with the South Korea data. We have tested and discussed the uncertainties of the model. We also have analyzed the trends in the confirmed cases using this model for the five most affected countries plus Brazil along several epidemic weeks.","PeriodicalId":106768,"journal":{"name":"Revista de Engenharia Térmica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124887646","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 : 2019-12-16DOI: 10.26678/abcm.cobem2017.cob17-1965
D. Módolo, L. Pereira, L. Micheli, W. K. D. C. Saruhashi
Vegetable oils, when subjected to transesterification process generate “vegetable oils esters”, with similar properties as density, cetane number, heating values, air-fuel ratio. However, problems resulting from the higher viscosity, leads to a worst spraying and combustion, formation of undesirable deposits on engine parts and contamination of the lubricant oil. Due to these problems, it is interesting to study an additive, also derived from biomass, to improve the characteristics of biodiesel for a suitable use in diesel engines. This paper proposes an additive (d-limonene obtained from orange peel) and preliminary results obtained from the tests in a stationary diesel engine fueled with mixtures of diesel/biodiesel/d-limonene, in different concentration to compare with a regular diesel-biodiesel blend and analyzes the influence of the additive on the combustion process. The diesel oil used was purchased from BR supply network (containing 7% biodiesel in its composition) and two blends with different concentrations of the additive (1% and 3% of d-limonene) were prepared and tested. Diesel without additive was also tested. The effects of the DS10 addititivation with d-limonene in the combustion process of a diesel engine have been analyzed, the results obtained were satisfactory showing the positive effects in the combustion process with the addition of d-limonene in diesel-biodiesel blends, decreasing the ignition delay around 2 degrees and showing an improvement in the cetane number of the fuel.
{"title":"COMBUSTION ANALYSIS OF D-LIMONENE AS AN ADDITIVE TO DIESEL-BIODIESEL BLENDS IN COMPRESSION IGNITION ENGINES","authors":"D. Módolo, L. Pereira, L. Micheli, W. K. D. C. Saruhashi","doi":"10.26678/abcm.cobem2017.cob17-1965","DOIUrl":"https://doi.org/10.26678/abcm.cobem2017.cob17-1965","url":null,"abstract":"Vegetable oils, when subjected to transesterification process generate “vegetable oils esters”, with similar properties as density, cetane number, heating values, air-fuel ratio. However, problems resulting from the higher viscosity, leads to a worst spraying and combustion, formation of undesirable deposits on engine parts and contamination of the lubricant oil. Due to these problems, it is interesting to study an additive, also derived from biomass, to improve the characteristics of biodiesel for a suitable use in diesel engines. This paper proposes an additive (d-limonene obtained from orange peel) and preliminary results obtained from the tests in a stationary diesel engine fueled with mixtures of diesel/biodiesel/d-limonene, in different concentration to compare with a regular diesel-biodiesel blend and analyzes the influence of the additive on the combustion process. The diesel oil used was purchased from BR supply network (containing 7% biodiesel in its composition) and two blends with different concentrations of the additive (1% and 3% of d-limonene) were prepared and tested. Diesel without additive was also tested. The effects of the DS10 addititivation with d-limonene in the combustion process of a diesel engine have been analyzed, the results obtained were satisfactory showing the positive effects in the combustion process with the addition of d-limonene in diesel-biodiesel blends, decreasing the ignition delay around 2 degrees and showing an improvement in the cetane number of the fuel.","PeriodicalId":106768,"journal":{"name":"Revista de Engenharia Térmica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123134835","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 : 2019-12-16DOI: 10.26678/abcm.cobem2017.cob17-2068
J. A. Souza, D. Adamatti, P. Montoya
In this work, Constructal Design and Genetic Algorithms are used to construct high conductivity paths connected to a heat sink and inserted in a square plate of low conductivity material with internal heat generation. The objective is propose a methodology that leads to minimize the maximum solid domain temperature. Total volume of the plate, amount of high thermal conductivity material and thermal ratio between high and low conductivities are fixed. The high conductive pathway forms found in this work greately resembles to the tree-forms found in nature, on which temperature is efficiently minimized by the application of the Genetic Algorithm and the Constructal Theory combined.
{"title":"CONDUCTIVE PATHWAYS CONSTRUCTION USING GENETIC ALGORITHM AND CONSTRUCTAL DESIGN","authors":"J. A. Souza, D. Adamatti, P. Montoya","doi":"10.26678/abcm.cobem2017.cob17-2068","DOIUrl":"https://doi.org/10.26678/abcm.cobem2017.cob17-2068","url":null,"abstract":"In this work, Constructal Design and Genetic Algorithms are used to construct high conductivity paths connected to a heat sink and inserted in a square plate of low conductivity material with internal heat generation. The objective is propose a methodology that leads to minimize the maximum solid domain temperature. Total volume of the plate, amount of high thermal conductivity material and thermal ratio between high and low conductivities are fixed. The high conductive pathway forms found in this work greately resembles to the tree-forms found in nature, on which temperature is efficiently minimized by the application of the Genetic Algorithm and the Constructal Theory combined.","PeriodicalId":106768,"journal":{"name":"Revista de Engenharia Térmica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129646146","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 : 2019-06-03DOI: 10.5380/RETERM.V18I1.67024
M. Redin, L. F. Bez, L. Rodrigues
This paper proposes a methodology for the estimation of a disk brake’s thermal load based on its vehicle’s velocity, where this thermal load serves as an input for a numerical simulation. The load is estimated through a balance between variation in the mechanical energy of the vehicle and the energy dissipated via aerodynamic and rolling drag forces. The RS Racing UFRGS team provided the vehicle’s data and geometry, and the velocity data was taken from a real endurance competition. The thermal load thus calculated is then used as input for a 3D transient finite element model containing the disk and the wheel hub. The results are consistent with what is expected by the RS Racing UFRGS team. Based on the results of the 3D transient model, two more simplified analysis are viable: one in permanent regime, which achieves a temperature distribution within the oscillation presented on the transient model; and also a 2D analysis which can be made by the replacement of the wheel hub with an equivalent global heat transfer coefficient.
本文提出了一种基于车辆速度估计盘式制动器热负荷的方法，其中热负荷作为数值模拟的输入。通过平衡车辆的机械能变化和通过空气动力和滚动阻力耗散的能量来估计负载。RS Racing UFRGS团队提供了车辆的数据和几何形状，速度数据取自真实的耐力赛。这样计算的热负荷然后被用作包含圆盘和轮毂的三维瞬态有限元模型的输入。结果与RS Racing UFRGS团队的预期一致。基于三维瞬态模型的结果，两种简化的分析是可行的:一种是在永久状态下，得到瞬态模型所呈现的振荡内的温度分布;用等效全局换热系数替换轮毂进行二维分析。
{"title":"VELOCITY-BASED MODELING OF THE THERMAL LOAD FOR A FORMULA SAE’S DISK BRAKE SIMULATION","authors":"M. Redin, L. F. Bez, L. Rodrigues","doi":"10.5380/RETERM.V18I1.67024","DOIUrl":"https://doi.org/10.5380/RETERM.V18I1.67024","url":null,"abstract":"This paper proposes a methodology for the estimation of a disk brake’s thermal load based on its vehicle’s velocity, where this thermal load serves as an input for a numerical simulation. The load is estimated through a balance between variation in the mechanical energy of the vehicle and the energy dissipated via aerodynamic and rolling drag forces. The RS Racing UFRGS team provided the vehicle’s data and geometry, and the velocity data was taken from a real endurance competition. The thermal load thus calculated is then used as input for a 3D transient finite element model containing the disk and the wheel hub. The results are consistent with what is expected by the RS Racing UFRGS team. Based on the results of the 3D transient model, two more simplified analysis are viable: one in permanent regime, which achieves a temperature distribution within the oscillation presented on the transient model; and also a 2D analysis which can be made by the replacement of the wheel hub with an equivalent global heat transfer coefficient.","PeriodicalId":106768,"journal":{"name":"Revista de Engenharia Térmica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127143338","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 : 2019-06-03DOI: 10.5380/RETERM.V18I1.67047
R. G. Hübner, P. Oleinik, W. C. Marques, M. N. Gomes, E. D. Santos, B. N. Machado, L. Isoldi
This work presents a numerical study to evaluate the difference between the fluid dynamic behavior of an overtopping device subjected to the incidence of a realistic wave when compared to a regular one; being this regular wave representative of the considered realistic sea state. To do so, the FLUENT software was employed, which is a Computational Fluid Dynamics package based on the Finite Volume Method. The regular wave was generated through a User Defined Function (UDF) that imposes its velocities components as boundary conditions of prescribed velocity. On the other hand, for the realistic wave it was used a methodology to impose the realistic components velocities from transient discrete values, named Table Data (TD) in FLUENT software. For both cases the Volume of Fluid (VOF) multiphase model was applied in the treatment of the water-air interaction. The results showed that the amount of water accumulated in the reservoir for the realistic sea state was 2.46 higher than for the regular wave. This is a relevant finding, since several researches about Overtopping device efficiency were promoted considering only the incidence of regular wave.
{"title":"NUMERICAL STUDY COMPARING THE INCIDENCE INFLUENCE BETWEEN REALISTIC WAVE AND REGULAR WAVE OVER AN OVERTOPPING DEVICE","authors":"R. G. Hübner, P. Oleinik, W. C. Marques, M. N. Gomes, E. D. Santos, B. N. Machado, L. Isoldi","doi":"10.5380/RETERM.V18I1.67047","DOIUrl":"https://doi.org/10.5380/RETERM.V18I1.67047","url":null,"abstract":"This work presents a numerical study to evaluate the difference between the fluid dynamic behavior of an overtopping device subjected to the incidence of a realistic wave when compared to a regular one; being this regular wave representative of the considered realistic sea state. To do so, the FLUENT software was employed, which is a Computational Fluid Dynamics package based on the Finite Volume Method. The regular wave was generated through a User Defined Function (UDF) that imposes its velocities components as boundary conditions of prescribed velocity. On the other hand, for the realistic wave it was used a methodology to impose the realistic components velocities from transient discrete values, named Table Data (TD) in FLUENT software. For both cases the Volume of Fluid (VOF) multiphase model was applied in the treatment of the water-air interaction. The results showed that the amount of water accumulated in the reservoir for the realistic sea state was 2.46 higher than for the regular wave. This is a relevant finding, since several researches about Overtopping device efficiency were promoted considering only the incidence of regular wave.","PeriodicalId":106768,"journal":{"name":"Revista de Engenharia Térmica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121348375","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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