Radial rotating oscillating heat pipes(R-OHPs)have excellent thermal performance and great potential for application in the thermal management of rotatory machinery.However,the heat transport behavior and temperature ...Radial rotating oscillating heat pipes(R-OHPs)have excellent thermal performance and great potential for application in the thermal management of rotatory machinery.However,the heat transport behavior and temperature characteristics of R-OHPs are complex,and their understanding is still limited,hence necessitating further research.In this study,thanks to an experimental investigation involving a copper R-OHP running with acetone and water,its thermal performance is evaluated,and then the temperature characteristics are analyzed by nonlinear dynamic analysis.The study reveals that the effective heat transfer coefficient of R-OHPs undergoes a notable increase with rising rotational speed,exhibiting a peak at a threshold speed value.Such a peak is present irrespectively of the working fluid,and,after exceeding the threshold,higher rotational speeds lead to a lower thermal performance.Based on nonlinear dynamic analysis,the power spectrum density of the evaporator temperature indicates a lack of dominant frequency in temperature signals,suggesting a complex behavior characterized by random oscillations of vapor slugs and liquid plugs.In order to better understand how strong the chaotic behavior is,an autocorrelation analysis was carried out,the OHP at static state has a stronger chaos than R-OHPs.The correlation dimension analysis of the evaporator temperature provides values ranging from 1.2 to 1.6,which together with the Lyapunov exponent calculations,further support an evident chaotic nature of R-OHPs.展开更多
Lane detection is a fundamental aspect of most current advanced driver assistance systems(ADASs). A large number of existing results focus on the study of vision-based lane detection methods due to the extensive knowl...Lane detection is a fundamental aspect of most current advanced driver assistance systems(ADASs). A large number of existing results focus on the study of vision-based lane detection methods due to the extensive knowledge background and the low-cost of camera devices. In this paper, previous visionbased lane detection studies are reviewed in terms of three aspects, which are lane detection algorithms, integration, and evaluation methods. Next, considering the inevitable limitations that exist in the camera-based lane detection system, the system integration methodologies for constructing more robust detection systems are reviewed and analyzed. The integration methods are further divided into three levels, namely, algorithm, system,and sensor. Algorithm level combines different lane detection algorithms while system level integrates other object detection systems to comprehensively detect lane positions. Sensor level uses multi-modal sensors to build a robust lane recognition system. In view of the complexity of evaluating the detection system, and the lack of common evaluation procedure and uniform metrics in past studies, the existing evaluation methods and metrics are analyzed and classified to propose a better evaluation of the lane detection system. Next, a comparison of representative studies is performed. Finally, a discussion on the limitations of current lane detection systems and the future developing trends toward an Artificial Society, Computational experiment-based parallel lane detection framework is proposed.展开更多
The introduction of the multi well plate miniaturisation technology with its associated automated dispensers, readers and integrated systems coupled with advances in life sciences has a propelling effect on the rate ...The introduction of the multi well plate miniaturisation technology with its associated automated dispensers, readers and integrated systems coupled with advances in life sciences has a propelling effect on the rate at which new potential drug molecules are discovered. The translation of these discoveries to real outcome now demands parallel approaches which allow large numbers of process options to be rapidly assessed. The engineering challenges in achieving this provide the motivation for the proposed work. In this work we used computational fluid dynamics(CFD) analysis to study flow conditions in a gas liquid contactor which has the potential to be used as a fermenter on a multi well format. The bioreactor had a working volume of 6 5 mL with the major dimensions equal to those of a single well of a 24 well plate. The 6 5 mL bioreactor was mechanically agitated and aerated by a single sparger placed beneath the bottom impeller. Detailed numerical procedure for solving the governing flow equations is given. The CFD results are combined with population balance equations to establish the size of the bubbles and their distribution in the bioreactor. Power curves with and without aeration are provided based on the simulated results.展开更多
This study aims at developing an optimization framework for electric vehicle charging by considering different trade-offs between battery degradation and charging time.For the first time,the application of practical l...This study aims at developing an optimization framework for electric vehicle charging by considering different trade-offs between battery degradation and charging time.For the first time,the application of practical limitations on charging and cooling power is considered along with more detailed health models.Lithium iron phosphate battery is used as a case study to demonstrate the effectiveness of the proposed optimization framework.A coupled electro-thermal equivalent circuit model is used along with two battery health models to mathematically obtain optimal charging current profiles by considering stress factors of state-of-charge,charging rate,temperature and time.The optimization results demonstrate an improvement over the benchmark constant current–constant voltage(CCCV)charging protocol when considering both the charging time and battery health.A main difference between the optimal and the CCCV charging protocols is found to be an additional ability to apply constraints and adapt to initial conditions in the proposed optimal charging protocol.In a case study,for example,the‘optimal time’charging is found to take 12 min while the‘optimal health’charging profile suggests around 100 min for charging the battery from 25 to 75%state-of-charge.Any other trade-off between those two extreme cases is achievable using the proposed charging protocol as well.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.52205476)Jiangsu Provincial Natural Science Foundation(Grant No.BK20242040)+2 种基金Fundamental Research Funds for the Central Universities(Grant No.NG2024008)the Youth Talent Support Project of CASTthe Fund of Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology(Grant No.1005-ZAA20003-14)。
文摘Radial rotating oscillating heat pipes(R-OHPs)have excellent thermal performance and great potential for application in the thermal management of rotatory machinery.However,the heat transport behavior and temperature characteristics of R-OHPs are complex,and their understanding is still limited,hence necessitating further research.In this study,thanks to an experimental investigation involving a copper R-OHP running with acetone and water,its thermal performance is evaluated,and then the temperature characteristics are analyzed by nonlinear dynamic analysis.The study reveals that the effective heat transfer coefficient of R-OHPs undergoes a notable increase with rising rotational speed,exhibiting a peak at a threshold speed value.Such a peak is present irrespectively of the working fluid,and,after exceeding the threshold,higher rotational speeds lead to a lower thermal performance.Based on nonlinear dynamic analysis,the power spectrum density of the evaporator temperature indicates a lack of dominant frequency in temperature signals,suggesting a complex behavior characterized by random oscillations of vapor slugs and liquid plugs.In order to better understand how strong the chaotic behavior is,an autocorrelation analysis was carried out,the OHP at static state has a stronger chaos than R-OHPs.The correlation dimension analysis of the evaporator temperature provides values ranging from 1.2 to 1.6,which together with the Lyapunov exponent calculations,further support an evident chaotic nature of R-OHPs.
文摘Lane detection is a fundamental aspect of most current advanced driver assistance systems(ADASs). A large number of existing results focus on the study of vision-based lane detection methods due to the extensive knowledge background and the low-cost of camera devices. In this paper, previous visionbased lane detection studies are reviewed in terms of three aspects, which are lane detection algorithms, integration, and evaluation methods. Next, considering the inevitable limitations that exist in the camera-based lane detection system, the system integration methodologies for constructing more robust detection systems are reviewed and analyzed. The integration methods are further divided into three levels, namely, algorithm, system,and sensor. Algorithm level combines different lane detection algorithms while system level integrates other object detection systems to comprehensively detect lane positions. Sensor level uses multi-modal sensors to build a robust lane recognition system. In view of the complexity of evaluating the detection system, and the lack of common evaluation procedure and uniform metrics in past studies, the existing evaluation methods and metrics are analyzed and classified to propose a better evaluation of the lane detection system. Next, a comparison of representative studies is performed. Finally, a discussion on the limitations of current lane detection systems and the future developing trends toward an Artificial Society, Computational experiment-based parallel lane detection framework is proposed.
文摘The introduction of the multi well plate miniaturisation technology with its associated automated dispensers, readers and integrated systems coupled with advances in life sciences has a propelling effect on the rate at which new potential drug molecules are discovered. The translation of these discoveries to real outcome now demands parallel approaches which allow large numbers of process options to be rapidly assessed. The engineering challenges in achieving this provide the motivation for the proposed work. In this work we used computational fluid dynamics(CFD) analysis to study flow conditions in a gas liquid contactor which has the potential to be used as a fermenter on a multi well format. The bioreactor had a working volume of 6 5 mL with the major dimensions equal to those of a single well of a 24 well plate. The 6 5 mL bioreactor was mechanically agitated and aerated by a single sparger placed beneath the bottom impeller. Detailed numerical procedure for solving the governing flow equations is given. The CFD results are combined with population balance equations to establish the size of the bubbles and their distribution in the bioreactor. Power curves with and without aeration are provided based on the simulated results.
文摘This study aims at developing an optimization framework for electric vehicle charging by considering different trade-offs between battery degradation and charging time.For the first time,the application of practical limitations on charging and cooling power is considered along with more detailed health models.Lithium iron phosphate battery is used as a case study to demonstrate the effectiveness of the proposed optimization framework.A coupled electro-thermal equivalent circuit model is used along with two battery health models to mathematically obtain optimal charging current profiles by considering stress factors of state-of-charge,charging rate,temperature and time.The optimization results demonstrate an improvement over the benchmark constant current–constant voltage(CCCV)charging protocol when considering both the charging time and battery health.A main difference between the optimal and the CCCV charging protocols is found to be an additional ability to apply constraints and adapt to initial conditions in the proposed optimal charging protocol.In a case study,for example,the‘optimal time’charging is found to take 12 min while the‘optimal health’charging profile suggests around 100 min for charging the battery from 25 to 75%state-of-charge.Any other trade-off between those two extreme cases is achievable using the proposed charging protocol as well.
