The Experts below are selected from a list of 1875 Experts worldwide ranked by ideXlab platform
Ming Yun Lv - One of the best experts on this subject based on the ideXlab platform.
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Optimization design of a thermal protection structure for the solar array of stratospheric Airships
Renewable Energy, 2019Co-Authors: Junhui Meng, Zhongbing Yao, Siyu Liu, Ming Yun LvAbstract:Abstract Renewable power system using solar array is one of the most critical subsystems for stratospheric Airships. It is important of thermal protection for the stratospheric airship, because excessive temperature of solar cell may reduce its conversion efficiency and age the envelope material underlaid solar cells. Multi-objective optimization of a thermal protection structure with heat dissipation and insulation layers for solar array of a stratospheric airship is performed in this paper. The optimization process is carried out by a Nondominated Sorting Genetic Algorithm to decrease the sensitivity toward weights or demand levels. The specific temperature difference, which indicates the ratio of temperature reduction and structure density, and the output power of solar array are used to present the optimization aims. Three geometric variables related to the number of fins, width ratio of fins and thickness ratio of dissipation and insulation layer are selected as the design variables. Pareto optimal fronts representing the trade-offs between the performance parameters are obtained at last and optimization results are compared with previous studies and the thermal protection effects and output power of the solar array are both more excellent. Furthermore, the simulation of the thermal protection structure with optimization parameters are carried out at last.
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thermal performance analysis of a high altitude solar powered hybrid airship
Renewable Energy, 2018Co-Authors: Lanchuan Zhang, Junhui Meng, Jun Li, Huafei Du, Ming Yun LvAbstract:Abstract The increasing application of hybrid Airships which have been recently proposed as high altitude platforms, makes it necessary for research into the thermal performance of such Airships that possess a photovoltaic module array(PVMA). In this study, a simplified thermal model of a high-altitude hybrid airship with a PVMA, was proposed that included direct solar, infrared, reflected, and scattered radiation and convective heat transfer. Based on computational fluid dynamics(CFD), a simulation methodology, using a user defined function(UDF) program, was introduced to investigate the PVMA's thermal effects on the hybrid airship. A ground experiment was also performed to validate this numerical method's effectiveness. Further simulations and discussion of temperature and velocity distributions of the hybrid airship's internal helium were conducted. The results showed that the PVMA atop the hull had large effects on the hybrid airship's thermal performance. The temperature distribution of the envelope varied greatly during the day and night because of the PVMA's influence as well as the internal helium flow. In addition, forced convection had little influence on the PVMA's output performance, which was analyzed in detail.
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Solar array layout optimization for stratospheric Airships using numerical method
Energy Conversion and Management, 2017Co-Authors: Ming Yun Lv, Jun Li, Huafei Du, Junhui MengAbstract:Abstract The solar array layout is one of the critical factors affecting the output performance of a solar array on a stratospheric airship. Optimizing the layout to improve output energy per day is very important for a long endurance vehicle, but the research about this subject is rare. This paper outlines a numerical method based on a rotating model of a stratospheric airship to optimize the solar array layout. Combined with the solar radiation model, the solar array layout optimization model applying genetic algorithm is developed using a MATLAB computer program in this paper. Compared with the design parameters of three stratospheric solar-powered Airships, the theoretical model is proved to be feasible. In the course of the study, the effects of the starting point and the central angle of solar array are discussed in detail. In addition, the optimal results of the solar array layout for four common situations are investigated using the method. The results indicate that this method is helpful in the preparation stage for installing large area flexible solar arrays.
Junhui Meng - One of the best experts on this subject based on the ideXlab platform.
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Optimization design of a thermal protection structure for the solar array of stratospheric Airships
Renewable Energy, 2019Co-Authors: Junhui Meng, Zhongbing Yao, Siyu Liu, Ming Yun LvAbstract:Abstract Renewable power system using solar array is one of the most critical subsystems for stratospheric Airships. It is important of thermal protection for the stratospheric airship, because excessive temperature of solar cell may reduce its conversion efficiency and age the envelope material underlaid solar cells. Multi-objective optimization of a thermal protection structure with heat dissipation and insulation layers for solar array of a stratospheric airship is performed in this paper. The optimization process is carried out by a Nondominated Sorting Genetic Algorithm to decrease the sensitivity toward weights or demand levels. The specific temperature difference, which indicates the ratio of temperature reduction and structure density, and the output power of solar array are used to present the optimization aims. Three geometric variables related to the number of fins, width ratio of fins and thickness ratio of dissipation and insulation layer are selected as the design variables. Pareto optimal fronts representing the trade-offs between the performance parameters are obtained at last and optimization results are compared with previous studies and the thermal protection effects and output power of the solar array are both more excellent. Furthermore, the simulation of the thermal protection structure with optimization parameters are carried out at last.
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thermal performance analysis of a high altitude solar powered hybrid airship
Renewable Energy, 2018Co-Authors: Lanchuan Zhang, Junhui Meng, Jun Li, Huafei Du, Ming Yun LvAbstract:Abstract The increasing application of hybrid Airships which have been recently proposed as high altitude platforms, makes it necessary for research into the thermal performance of such Airships that possess a photovoltaic module array(PVMA). In this study, a simplified thermal model of a high-altitude hybrid airship with a PVMA, was proposed that included direct solar, infrared, reflected, and scattered radiation and convective heat transfer. Based on computational fluid dynamics(CFD), a simulation methodology, using a user defined function(UDF) program, was introduced to investigate the PVMA's thermal effects on the hybrid airship. A ground experiment was also performed to validate this numerical method's effectiveness. Further simulations and discussion of temperature and velocity distributions of the hybrid airship's internal helium were conducted. The results showed that the PVMA atop the hull had large effects on the hybrid airship's thermal performance. The temperature distribution of the envelope varied greatly during the day and night because of the PVMA's influence as well as the internal helium flow. In addition, forced convection had little influence on the PVMA's output performance, which was analyzed in detail.
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Solar array layout optimization for stratospheric Airships using numerical method
Energy Conversion and Management, 2017Co-Authors: Ming Yun Lv, Jun Li, Huafei Du, Junhui MengAbstract:Abstract The solar array layout is one of the critical factors affecting the output performance of a solar array on a stratospheric airship. Optimizing the layout to improve output energy per day is very important for a long endurance vehicle, but the research about this subject is rare. This paper outlines a numerical method based on a rotating model of a stratospheric airship to optimize the solar array layout. Combined with the solar radiation model, the solar array layout optimization model applying genetic algorithm is developed using a MATLAB computer program in this paper. Compared with the design parameters of three stratospheric solar-powered Airships, the theoretical model is proved to be feasible. In the course of the study, the effects of the starting point and the central angle of solar array are discussed in detail. In addition, the optimal results of the solar array layout for four common situations are investigated using the method. The results indicate that this method is helpful in the preparation stage for installing large area flexible solar arrays.
Josue J G Ramos - One of the best experts on this subject based on the ideXlab platform.
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project aurora infrastructure and flight control experiments for a robotic airship
Journal of Field Robotics, 2006Co-Authors: Ely Carneiro De Paiva, José Raul Azinheira, Josue J G Ramos, Alexandra Moutinho, S S BuenoAbstract:Project AURORA aims at the development of unmanned robotic Airships capable of autonomous flight over user-defined locations for aerial inspection and environmental monitoring missions. In this article, the authors report a successful control and navigation scheme for a robotic airship flight path following. First, the AURORA airship, software environment, onboard system, and ground station infrastructures are described. Then, two main approaches for the automatic control and navigation system of the airship are presented. The first one shows the design of dedicated controllers based on the linearized dynamics of the vehicle. Following this methodology, experimental results for the airship flight path following through a set of predefined points in latitude/longitude, along with automatic altitude control are presented. A second approach considers the design of a single global nonlinear control scheme, covering all of the aerodynamic operational range in a sole formulation. Nonlinear control solutions under investigation for the AURORA airship are briefly described, along with some preliminary simulation results. © 2006 Wiley Periodicals, Inc.
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development of a vrml java unmanned airship simulating environment
Intelligent Robots and Systems, 1999Co-Authors: Josue J G Ramos, Marcel Bergerman, S S Bueno, Silvio M Maeta, Luiz G B Mirisola, A BruciapagliaAbstract:We present one of the first Internet-accessible airship simulators, based on a comprehensive airship dynamic model. The simulator is meant to be used as a tool for the development of control and navigation methods for autonomous and semi-autonomous robotic Airships and as testbed for airship pilot training. Realistic views of both the airship in flight and that of a virtual pilot are provided, as are commands to apply thrust to the engines, swivel them up and down, and deflect the control surfaces. This work is significant for providing robotics researchers with means to safely experiment with airship control.
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a semi autonomous robotic airship for environmental monitoring missions
International Conference on Robotics and Automation, 1998Co-Authors: Alberto Elfes, Marcel Bergerman, S S Bueno, Josue J G RamosAbstract:This paper discusses Project AURORA (autonomous unmanned remote monitoring robotic airship) which focuses on the development of the control, navigation, sensing, and inference technologies required for substantially autonomous robotic Airships. Our target application areas include the use of robotic Airships for environmental, biodiversity, and climate research and monitoring. Based on typical mission requirements, we present arguments that favour Airships over airplanes and helicopters as the ideal platforms for such missions. We outline the overall system architecture of the AURORA robotic airship, discuss its main subsystems, and mention the research and development issues involved.
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airship dynamic modeling for autonomous operation
International Conference on Robotics and Automation, 1998Co-Authors: S B V Gomes, Josue J G RamosAbstract:We present a comprehensive description of the physical principles of robotic airship operation, along with their dynamic model in a form suited for controller design and computer simulation. Based on the dynamic model, airship response modes are analyzed and control challenges are pointed out. The present work provides a starting point for robotics and control researchers interested in utilizing Airships as robotic aerial vehicles.
Chunlei Liu - One of the best experts on this subject based on the ideXlab platform.
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Thermal characteristics and output power performances analysis of solar powered stratospheric Airships
Applied Thermal Engineering, 2017Co-Authors: Daoming Xing, Qiumin Dai, Chunlei LiuAbstract:Abstract Thermal characteristics and output power performances are important factors to be considered in the design and operation of long endurance stratospheric Airships. The thermal and output power models of stratospheric Airships with solar array are established in this paper. Based on the models, a numerical simulation program is developed. The thermal and output power performances of a solar powered airship are simulated. The effects of solar array on the thermal performances of a stratospheric airship are discussed. The factors affecting the output power of solar cells are studied in detail. The results are conducive to understanding the thermal and output power behaviors of solar powered stratospheric Airships.
Daoming Xing - One of the best experts on this subject based on the ideXlab platform.
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Conceptual Design of an Energy System for High Altitude Airships Considering Thermal Effect
'MDPI AG', 2021Co-Authors: Qiumin Dai, Xiande Fang, Daoming Xing, Yingjie ZhaoAbstract:High altitude Airships possess tremendous potential for long-endurance spot hovering platforms for both commercial and strategic applications. The energy system, which is mainly made up of solar array and regenerative fuel cell, is the key component of a high altitude airship. The thermal effect is a major factor that affects the performance of the energy system of long endurance stratospheric vehicles. In this paper, a conceptual design method focusing on the thermal and power characteristics of an energy system for stratospheric Airships is proposed. The effect of thermal behavior of solar array on the energy system is analyzed. An optimized case is obtained on the consideration of power supply, thermal behaviors of helium and solar array. Results show that the maximum temperature difference of the solar array may be reduced by about 20 K and the mass of payload can be improved by up to 5%
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Thermal characteristics and output power performances analysis of solar powered stratospheric Airships
Applied Thermal Engineering, 2017Co-Authors: Daoming Xing, Qiumin Dai, Chunlei LiuAbstract:Abstract Thermal characteristics and output power performances are important factors to be considered in the design and operation of long endurance stratospheric Airships. The thermal and output power models of stratospheric Airships with solar array are established in this paper. Based on the models, a numerical simulation program is developed. The thermal and output power performances of a solar powered airship are simulated. The effects of solar array on the thermal performances of a stratospheric airship are discussed. The factors affecting the output power of solar cells are studied in detail. The results are conducive to understanding the thermal and output power behaviors of solar powered stratospheric Airships.