Pub Date : 1900-01-01DOI: 10.5923/j.jmea.20150504.01
E. A. Lima, M. Silveira, José Avila Júnior, Carlos Aureio, Silva Carvalho, Maria Fernanda Lousada Antunes, D. Junqueira
In the design of automotive components the use of numerical simulations has contributed to reducing the design time, decreasing the prototypes costs and increasing reliability of the final product. However is necessary a investigation on human body vertical vibrations transmitted by different types of vehicle for the purpose of recognition the danger and guiding to eliminate of risks of discomfort theirs. This study, the object is to compare the discomfort levels of occupants when different vehicles (car, bike and bus) move over a speed bump. The results show that wheelbase, wheel size and vehicle weight can lead to different vehicular discomfort results. Results of the study demonstrated that heavy vehicles occupants (bus or truck) are subject to discomfort greater than occupants of light vehicles (cars and motorcycles) ones.
{"title":"Evaluation of Vehicular Discomfort Measures Produced by Speed Bumps Using Numerical Simulation","authors":"E. A. Lima, M. Silveira, José Avila Júnior, Carlos Aureio, Silva Carvalho, Maria Fernanda Lousada Antunes, D. Junqueira","doi":"10.5923/j.jmea.20150504.01","DOIUrl":"https://doi.org/10.5923/j.jmea.20150504.01","url":null,"abstract":"In the design of automotive components the use of numerical simulations has contributed to reducing the design time, decreasing the prototypes costs and increasing reliability of the final product. However is necessary a investigation on human body vertical vibrations transmitted by different types of vehicle for the purpose of recognition the danger and guiding to eliminate of risks of discomfort theirs. This study, the object is to compare the discomfort levels of occupants when different vehicles (car, bike and bus) move over a speed bump. The results show that wheelbase, wheel size and vehicle weight can lead to different vehicular discomfort results. Results of the study demonstrated that heavy vehicles occupants (bus or truck) are subject to discomfort greater than occupants of light vehicles (cars and motorcycles) ones.","PeriodicalId":383435,"journal":{"name":"Journal of Mechanical Engineering and Automation","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122489622","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 : 1900-01-01DOI: 10.5923/j.jmea.20140402.04
Fagner Luis Goulart Dias, M. António, R. D. Nascimento, Lucilene de Oliveira Rodrigues
The gas turbine combustion chamber is one of the most critical components to be designed, because it must ensure a stable operation in a wide range of air/fuel ratio and load. Among several calculations involved in the design of a combustion chamber, the reference area is the most important physical parameter, especially by the great impact on other dimensions. In general, this parameter must be calculated from an analysis of the limitations imposed both chemical reactions and aerodynamics, i.e., based on combustion process requirements and maximum pressure drop allowable in the combustion chamber, respectively. So, the aim of this paper is investigate the influence of the reference area in the velocity profile, in the temperature distribution, in the mixing process and in the flame behavior, according to the reference area used in the combustion chamber. These numerical analyses were carried out using ANSYS CFX®, comparing them with the base value calculated by Lefebvre (5), for a thermodynamic cycle of 600 kW gas turbine engine, conduced in GateCycle® program. Finally, it can be concluded that some changes in the reference area calculated by Lefebvre (4) produces better results, especially by improving the burning process and the behavior of the flame.
{"title":"Reference Area Investigation in a Gas Turbine Combustion Chamber Using CFD","authors":"Fagner Luis Goulart Dias, M. António, R. D. Nascimento, Lucilene de Oliveira Rodrigues","doi":"10.5923/j.jmea.20140402.04","DOIUrl":"https://doi.org/10.5923/j.jmea.20140402.04","url":null,"abstract":"The gas turbine combustion chamber is one of the most critical components to be designed, because it must ensure a stable operation in a wide range of air/fuel ratio and load. Among several calculations involved in the design of a combustion chamber, the reference area is the most important physical parameter, especially by the great impact on other dimensions. In general, this parameter must be calculated from an analysis of the limitations imposed both chemical reactions and aerodynamics, i.e., based on combustion process requirements and maximum pressure drop allowable in the combustion chamber, respectively. So, the aim of this paper is investigate the influence of the reference area in the velocity profile, in the temperature distribution, in the mixing process and in the flame behavior, according to the reference area used in the combustion chamber. These numerical analyses were carried out using ANSYS CFX®, comparing them with the base value calculated by Lefebvre (5), for a thermodynamic cycle of 600 kW gas turbine engine, conduced in GateCycle® program. Finally, it can be concluded that some changes in the reference area calculated by Lefebvre (4) produces better results, especially by improving the burning process and the behavior of the flame.","PeriodicalId":383435,"journal":{"name":"Journal of Mechanical Engineering and Automation","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130568780","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 : 1900-01-01DOI: 10.5923/j.jmea.20150502.03
Fagner Luis Goulart Dias, M. Nascimento, Lucilene de Oliveira Rodrigues
Despite the significant advances achieved through the years, researchers in numerical simulation has investigated symmetry and periodicity conditions to reduce the computational time. Especially, it becomes essential this assessment in problems involving both combustion and detailed reactions mechanisms, as well as when new technologies are being evaluated. Therefore, aerothermodynamics conditions in a given periodic section, will be considered in the opposite section, assuming identical conditions in other sectors that compose the full scale domain. At this point, the definition of this representative region has been a major source of errors once the selected sector can not represent the full domain, leading to coarse approximations of the real phenomenon. In this context, this paper investigates the effects of periodicity and symmetry condition in a burner designed for flameless combustion regime. This new combustion system exhibits a strong internal recirculation and very specific characteristics that can contribute to the flow profile. Numerical simulations were performed in ANSYS FLUENT®. Based on the results, the periodicity condition in a 1/16 sector showed discordant results with those obtained in the simulations with a full scale burner and by comparing with the experimental data available. However, by employing the symmetry condition, numerical results were close to those results involving a full scale domain, reinforcing the importance of investigate carefully the use of such strategies.
{"title":"Aerodynamic Assessment of Periodicity and Symmetry Conditions in a Flameless Burner","authors":"Fagner Luis Goulart Dias, M. Nascimento, Lucilene de Oliveira Rodrigues","doi":"10.5923/j.jmea.20150502.03","DOIUrl":"https://doi.org/10.5923/j.jmea.20150502.03","url":null,"abstract":"Despite the significant advances achieved through the years, researchers in numerical simulation has investigated symmetry and periodicity conditions to reduce the computational time. Especially, it becomes essential this assessment in problems involving both combustion and detailed reactions mechanisms, as well as when new technologies are being evaluated. Therefore, aerothermodynamics conditions in a given periodic section, will be considered in the opposite section, assuming identical conditions in other sectors that compose the full scale domain. At this point, the definition of this representative region has been a major source of errors once the selected sector can not represent the full domain, leading to coarse approximations of the real phenomenon. In this context, this paper investigates the effects of periodicity and symmetry condition in a burner designed for flameless combustion regime. This new combustion system exhibits a strong internal recirculation and very specific characteristics that can contribute to the flow profile. Numerical simulations were performed in ANSYS FLUENT®. Based on the results, the periodicity condition in a 1/16 sector showed discordant results with those obtained in the simulations with a full scale burner and by comparing with the experimental data available. However, by employing the symmetry condition, numerical results were close to those results involving a full scale domain, reinforcing the importance of investigate carefully the use of such strategies.","PeriodicalId":383435,"journal":{"name":"Journal of Mechanical Engineering and Automation","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132265178","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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