An integrated simulation system for solar sail spacecraft with individually controllable elements(SSICE)is investigated in this paper,including the modelling of power management,thermal control,attitude control,umbra ...An integrated simulation system for solar sail spacecraft with individually controllable elements(SSICE)is investigated in this paper,including the modelling of power management,thermal control,attitude control,umbra prediction,and orbit prediction subsystems.Considering the self-control and reactivity subsystems,an agent based method is applied to develop the subsystem models.Each subsystem is an individual agent component,which manages itself autonomously and reacts to the requirements from other agents.To reduce computing burden on a specified computer and improve the suitability and flexibility of the integrated simulation system,a distributed framework is employed in the system by deploying agent components on different computers.The data transmission among agents is based on the transmission control protocol/Internet protocol(TCP/IP).A practical example of sun pointing is used to test the operating effect of the integrated system and the working condition of subsystems.The simulation results verify that the integrated system has higher sun pointing accuracy,quicker dynamical response to variations of the lighting,attitude and temperature and fewer computing resources with effective and accurate subsystems.The integrated system proposed in this paper can be applied to solar sail design,operation,and mission planning.展开更多
The article presents a structural analysis of a new space probe-solar sail.It was deployed successfully on ground.The loads for an outer space mission was introduced and expressed with equation.As a special state,the ...The article presents a structural analysis of a new space probe-solar sail.It was deployed successfully on ground.The loads for an outer space mission was introduced and expressed with equation.As a special state,the largest load around earth was used to analyze the model by the finite element method.Some results about strain and stress was obtained after setting some initial parameters.Compared to the results in the literature,the results presented here are significant.展开更多
研究潜艇在斜航工况下的水动力特性对潜艇操纵性的影响至关重要。本文使用雷诺平均RANS(Reynolds Average Navier-Stockes)与分离涡DES(Detached-Eddy Simulation)2种数值方法,对Joubert BB2潜艇在斜航工况下水动力性能及周围流场进行...研究潜艇在斜航工况下的水动力特性对潜艇操纵性的影响至关重要。本文使用雷诺平均RANS(Reynolds Average Navier-Stockes)与分离涡DES(Detached-Eddy Simulation)2种数值方法,对Joubert BB2潜艇在斜航工况下水动力性能及周围流场进行数值模拟。分析不同漂角工况下潜艇所受力、力矩及周围流场,重点关注围壳及尾舵附近流场,探寻漂角变化对潜艇受力及流场的影响。结果显示,采用DES方法计算大漂角工况时误差更小同时流场信息捕捉更加精确。研究结果表明,潜艇大漂角工况下采用DES方法能够更加准确地模拟潜艇受力及流场,同时对研究潜艇斜航状态下的流动分离现象具有一定的参考价值。展开更多
基金This work was supported by the National Natural Science Foundation of China(11772024).
文摘An integrated simulation system for solar sail spacecraft with individually controllable elements(SSICE)is investigated in this paper,including the modelling of power management,thermal control,attitude control,umbra prediction,and orbit prediction subsystems.Considering the self-control and reactivity subsystems,an agent based method is applied to develop the subsystem models.Each subsystem is an individual agent component,which manages itself autonomously and reacts to the requirements from other agents.To reduce computing burden on a specified computer and improve the suitability and flexibility of the integrated simulation system,a distributed framework is employed in the system by deploying agent components on different computers.The data transmission among agents is based on the transmission control protocol/Internet protocol(TCP/IP).A practical example of sun pointing is used to test the operating effect of the integrated system and the working condition of subsystems.The simulation results verify that the integrated system has higher sun pointing accuracy,quicker dynamical response to variations of the lighting,attitude and temperature and fewer computing resources with effective and accurate subsystems.The integrated system proposed in this paper can be applied to solar sail design,operation,and mission planning.
基金Supported by National Natural Science Foundation of China(10575097,10775128)The"Hundred Talented"Projects from Chinese Academy of Science,National Key Basic Research Program(2006CB303102),SRFDP(20060358050),111Projects(B07033)
文摘The article presents a structural analysis of a new space probe-solar sail.It was deployed successfully on ground.The loads for an outer space mission was introduced and expressed with equation.As a special state,the largest load around earth was used to analyze the model by the finite element method.Some results about strain and stress was obtained after setting some initial parameters.Compared to the results in the literature,the results presented here are significant.
文摘研究潜艇在斜航工况下的水动力特性对潜艇操纵性的影响至关重要。本文使用雷诺平均RANS(Reynolds Average Navier-Stockes)与分离涡DES(Detached-Eddy Simulation)2种数值方法,对Joubert BB2潜艇在斜航工况下水动力性能及周围流场进行数值模拟。分析不同漂角工况下潜艇所受力、力矩及周围流场,重点关注围壳及尾舵附近流场,探寻漂角变化对潜艇受力及流场的影响。结果显示,采用DES方法计算大漂角工况时误差更小同时流场信息捕捉更加精确。研究结果表明,潜艇大漂角工况下采用DES方法能够更加准确地模拟潜艇受力及流场,同时对研究潜艇斜航状态下的流动分离现象具有一定的参考价值。
文摘为有效预测船舶油耗,提出一种基于混合核函数的船舶油耗预测模型。分别构建径向基函数(radial basis function,RBF)和多项式单核函数的支持向量回归(support vector regression,SVR)模型,并利用自适应随机搜索(adaptive random search,ARS)算法对两者进行优化。在此基础上,建立基于混合核函数ARS-SVR的船舶油耗预测模型。以一艘风帆助航的大型原油运输船(very large crude carrier,VLCC)为研究对象,基于实船监测数据开展船舶油耗预测。结果表明,与单一的RBF和多项式单核ARS-SVR相比,采用混合核函数ARS-SVR的模型的预测结果的均方根误差分别降低了19.8%和30.2%。所提出的船舶油耗预测模型可以提升风帆助航船油耗计算的准确率,有助于优化船舶能效和提升管理技术。
