|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Aerodynamic/Stealthy/Structural Multidisciplinary Design Optimization of Unmanned Combat Air Vehicle显示文摘An optimization strategy is proposed to deal with the aerodynamic/stealthy/structural multidisciplinary design optimization(MDO) issue of unmanned combat air vehicle(UCAV).In applying the strategy,the MDO process is divided into two levels,i.e.system level optimization and subsystem level optimization.The system level optimization is to achieve optimized system objective(or multi-objective) through the adjustment of global external configuration design variables.The subsystem level optimization consists of the aerodynamic/stealthy integrated design and the structural optimization.The aerodynamic/stealthy integrated design aims at achieving the minimum aerodynamic drag coefficient under the constraint of stealthy requirement through the adjustment of local external configuration design variables.The structural optimization is to minimize the structural weight by adjusting the dimensions of structural components.A flowchart to implement this strategy is presented.The MDO for a flying-wing configuration of UCAV is employed to illustrate the detailed process of the optimization.The results indicate that the overall process of the surrogate-based two-level optimization strategy can be implemented automatically,and quite reasonable results are obtained. | Hu Tianyuan,Yu Xiongqing Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China | 2009 | Chinese Journal of Aeronautics2009，22，4： | 21 |
| 2 | Multi-objective optimization of aircraft design for emission and cost reductions显示文摘Pollutant gases emitted from the civil jet are doing more and more harm to the environment with the rapid development of the global commercial aviation transport. Low environmental impact has become a new requirement for aircraft design. In this paper,estimation method for emission in aircraft conceptual design stage is improved based on the International Civil Aviation Organization(ICAO) aircraft engine emissions databank and the polynomial curve fitting methods. The greenhouse gas emission(CO2equivalent) per seat per kilometer is proposed to measure the emissions. An approximate sensitive analysis and a multi-objective optimization of aircraft design for tradeoff between greenhouse effect and direct operating cost(DOC) are performed with five geometry variables of wing configuration and two flight operational parameters. The results indicate that reducing the cruise altitude and Mach number may result in a decrease of the greenhouse effect but an increase of DOC. And the two flight operational parameters have more effects on the emissions than the wing configuration. The Pareto-optimal front shows that a decrease of 29.8% in DOC is attained at the expense of an increase of 10.8% in greenhouse gases. | Wang Yu Yin Hailian Zhang Shuai Yu Xiongqing | 2014 | Chinese Journal of Aeronautics2014，27，1： | 17 |
| 3 | Multipoint optimization on fuel efficiency in conceptual design of wide-body aircraft显示文摘Aircraft conceptual design optimizations that maximize the performance at a design condition(single-point) may result in designs with unsatisfying off-design performance.To further improve aircraft efficiency under actual flight operations, there is a need to consider multiple flight conditions(multipoint) in aircraft conceptual design and optimization.A new strategy for multipoint optimizations in aircraft conceptual design is proposed in this paper.A wide-body aircraft is taken as an example for both single-point and multipoint optimizations with the objective of maximizing the specific hourly productivity.Boeing 787-8 flight data was used in the multipoint optimization to reflect the true objective function.The results show that the optimal design from the multipoint optimization has a 7.72% total specific hourly productivity increase of entire flight missions compared with that of the baseline aircraft, while the increase in the total specific hourly productivity from the single-point optimal design is only 5.73%.The differences between the results of single-point and multipoint optimizations indicate that there is a good option to further improve aircraft efficiency by considering actual flight conditions in aircraft conceptual design and optimization. | Xiao CHAI Xiongqing YU Yu WANG | 2018 | Chinese Journal of Aeronautics2018，31，1： | 7 |
| 4 | A Rapid Analysis Tool for Aerodynamics/Aerothermodynamics of Hypersonic Vehicles显示文摘A rapid engineering surface panel method to analyze aerodynamics and aerothermodynamics of hypersonic vehicles is developed.To obtain the surface pressure distribution of a hypersonic vehicle,the local surface inclination method is applied to calculate the pressure coefficient for each surface panel element,of which the normal vector is corrected first by using an efficient data structure and Rey-casting algorithm,local Reynolds numbers are calculated according to the geometric streamline method,then the aerodynamic heating flux is computed by both reference enthalpy relations and Reynolds analogy method.Several typical test cases are performed and the results indicate that,the developed tool is effective in predicting the aerodynamics/aerothermodynamics for complex geometry of hypersonic vehicle in a wide range of Mach numbers with a sufficient accuracy. | Li Zhengzhou Xiao Tianhang Lü Fanxi Yu Xiongqing Zhang Zhenming Du Sha | 2017 | Transactions of Nanjing University of Aeronautics and Astronautics2017，34，4： | 7 |
| 5 | Stand basal area modelling for Chinese fir plantations using an artificial neural network model显示文摘Artificial neural network models are a popular estimation tool for fitting nonlinear relationships because they require no assumptions about the form of the fitting function,non-Gaussian distributions,multicollinearity,outliers and noise in the data.The problems of backpropagation models using artificial neural networks include determination of the structure of the network and overlearning courses.According to data from 1981 to 2008 from 15 permanent sample plots on Dagangshan Mountain in Jiangxi Province,a back-propagation artificial neural network model(BPANN)and a support vector machine model(SVM)for basal area of Chinese fir(Cunninghamia lanceolata)plantations were constructed using four kinds of prediction factors,including stand age,site index,surviving stem numbers and quadratic mean diameters.Artificial intelligence methods,especially SVM,could be effective in describing stand basal area growth of Chinese fir under different growth conditions with higher simulation precision than traditional regression models.SVM and the Chapman–Richards nonlinear mixed-effects model had less systematic bias than the BPANN. | Shaohui Che Xiaohong Tan Congwei Xiang Jianjun Sun Xiaoyan Hu Xiongqing Zhang Aiguo Duan Jianguo Zhang | 2019 | Journal of Forestry Research2019，30，5： | 4 |
| 6 | A fast and automatic full-potential finite volume solver on Cartesian grids for unconventional configurations显示文摘To meet the requirements of fast and automatic computation of subsonic and transonic aerodynamics in aircraft conceptual design,a novel finite volume solver for full potential flows on adaptive Cartesian grids is developed in this paper.Cartesian grids with geometric adaptation are firstly generated automatically with boundary cells processed by cell-cutting and cell-merging algorithms.The nonlinear full potential equation is discretized by a finite volume scheme on these Cartesian grids and iteratively solved in an implicit fashion with a generalized minimum residual(GMRES) algorithm.During computation,solution-based mesh adaptation is also applied so as to capture flow features more accurately.An improved ghost-cell method is proposed to implement the non-penetration wall boundary condition where the velocity-potential of a ghost cell is modified by an analytic method instead.According to the characteristics of the Cartesian grids,the Kutta condition is applied by specially computing the gradients on Kutta-faces without directly assigning the potential jump to cells adjacent wake faces,which can significantly improve the solution converging speed.The feasibility and accuracy of the proposed method are validated by several typical cases of sub/transonic flows around an ONERA M6 wing,a DLR-F4 wing-body,and an unconventional figuration of a blended wing body(BWB).The validation cases demonstrate a fast convergence with fully automatic grid treatment and computation,and the results suggest its capacity in application for aircraft conceptual design. | Fanxi LYU Tianhang XIAO Xiongqing YU | 2017 | Chinese Journal of Aeronautics2017，30，3： | 4 |
| 7 | Shock control bump optimization for a low sweep supercritical wing显示文摘Shock control bumps are a promising technique in reducing wave drag of civil transport aircraft flying at transonic speeds.This paper investigates the optimization of 3D shock control bumps on a supercritical wing with a sweep angle of 16°at the1/4 chord.A similar supercritical wing with a higher sweep angle of 24.5°at the 1/4 chord has been adopted as a baseline for the study.Numerical results show that the drag coefficient of the low sweep wing with the optimized 3D shock control bumps is reduced below that for the high sweep wing,indicating shock control bumps can be used as an effective means to reduce the wave drag caused by reducing the wing sweep angle.From the point of view of the wing structure design,lower sweep angle will also bring the benefits of weight reduction,resulting in further fuel reduction. | DENG Feng QIN Ning LIU XueQiang YU XiongQing ZHAO Ning | 2013 | Science China(Technological Sciences)2013，56，10： | 4 |
| 8 | Integration of Manufacturing Cost into Structural Optimization of Composite Wings显示文摘The manufacturing cost is a significant factor that must be considered in the structural design of a composite wing.A multi-objective optimization method for the tradeoff between manufacturing cost and weight of composite wing structure is developed by integrating the manufacturing cost model into the traditional wing structural optimization.A two-level optimization method is proposed to carry out the tradeoff between manufacturing cost and weight,in which the design variables include both structural layout and dimensions and a cost model is incorporated into structural optimization.The manufacturing cost model for a composite wing and the detail procedure for solving this tradeoff problem are presented.The application of the method to the composite wing structural design of an unmanned aerial vehicle is illustrated to verify the method.The application indicates that the method is able to find the Pareto optimal set of minimum structural weight and manufacturing cost.Based on the Pareto optimal set,one can conduct the tradeoff between manufacturing cost and weight of wing structures. | Yin Hailian Yu Xiongqing | 2010 | Chinese Journal of Aeronautics2010，23，6： | 3 |
| 9 | Identification of encoding proteins related to SARS-CoV显示文摘By sampling 100 encoding proteins from SARS-coronavirus (SARS-CoV, NC 004718) and other six coronaviruses and selecting 23 variables through stepwise multiple regression (SMR) from 172 variables, the multiple linear regression (MLR) model was established with good results of the quantitative modelling correlation coefficient R2 = 0.645 and the cross-validation correlation coefficient RCV = 0.375. After removing 4 outliers, the quantitative 2 modelling and cross-validation correlation coefficients were R2= 0.743 and RCV = 0.543, respectively. | MEIHu SUNLili ZHOUYuan XIONGQing LIhiliang | 2004 | Chinese Science Bulletin2004，49，19： | 2 |
| 10 | Reliability analysis based on a novel density estimation method for structures with correlations显示文摘Estimating the Probability Density Function(PDF) of the performance function is a direct way for structural reliability analysis,and the failure probability can be easily obtained by integration in the failure domain.However,efficiently estimating the PDF is still an urgent problem to be solved.The existing fractional moment based maximum entropy has provided a very advanced method for the PDF estimation,whereas the main shortcoming is that it limits the application of the reliability analysis method only to structures with independent inputs.While in fact,structures with correlated inputs always exist in engineering,thus this paper improves the maximum entropy method,and applies the Unscented Transformation(UT) technique to compute the fractional moments of the performance function for structures with correlations,which is a very efficient moment estimation method for models with any inputs.The proposed method can precisely estimate the probability distributions of performance functions for structures with correlations.Besides,the number of function evaluations of the proposed method in reliability analysis,which is determined by UT,is really small.Several examples are employed to illustrate the accuracy and advantages of the proposed method. | Baoyu LI Leigang ZHANG Xuejun ZHU Xiongqing YU Xiaodong MA | 2017 | Chinese Journal of Aeronautics2017，30，3： | 2 |
| 11 | Multidisei- plinary design optimization of an electric-powered unmanned air vehicle 显示文摘 | Batill S M Stelmack M A Yu Xiongqing | 1999 | Aircraft Design1999，2，1： | 1 |
| 12 | Structural mass prediction in conceptual design of blended-wing-body aircraft显示文摘The Blended-Wing-Body(BWB) is an unconventional configuration of aircraft and considered as a potential configuration for future commercial aircraft. One of the difficulties in conceptual design of a BWB aircraft is structural mass prediction due to its unique structural feature. This paper presents a structural mass prediction method for conceptual design of BWB aircraft using a structure analysis and optimization method combined with empirical calibrations. The total BWB structural mass is divided into the ideal load-carrying structural mass, non-ideal mass, and secondary structural mass. Structural finite element analysis and optimization are used to predict the ideal primary structural mass, while the non-ideal mass and secondary structural mass are estimated by empirical methods. A BWB commercial aircraft is used to demonstrate the procedure of the BWB structural mass prediction method. The predicted mass of structural components of the BWB aircraft is presented, and the ratios of the structural component mass to the Maximum TakeOff Mass(MTOM) are discussed. It is found that the ratio of the fuselage mass to the MTOM for the BWB aircraft is much higher than that for a conventional commercial aircraft, and the ratio of the wing mass to the MTOM for the BWB aircraft is slightly lower than that for a conventional aircraft. | Wensheng ZHU Zhouwei FAN Xiongqing YU | 2019 | Chinese Journal of Aeronautics2019，32，11： | 1 |
| 13 | Analysis on water resources capacity in Chongqing(重庆市水资源承载力分析[J]显示文摘 | HEL(河凌) DENGCG(邓春光) XIONGQ(熊强) | | 安徽农业科学0，，： | 1 |
| 14 | Eukaryotic Promoter Recognition Using Back propagation Neural Network显示文摘A new system is developed to recognize promoter sequences from non promoter sequences based on position weight matrix and backpropagation neural network in this paper. The system performs significantly better on the training set and the test set, the mean recognition rate is as high as 99% on the training set and 97% on the testing set. Experimental results demonstrate the effectiveness of the system to recognize the promoter sequences that have been trained and the promoter sequences that have not been seen previously. | XIONGQing WANGYuan-Qiang LIZhi-Liang | 2004 | Chinese Journal of Biomedical Engineering(English Edition)2004，13，2： | 1 |
| 15 | Polysaccharidefrom fuzi(FPS)prevents hypercholesterolemia in rats显示文摘 | HUANG Xiongqing TANG Jun ZHOU Qin | 2010 | LipidsHealth Dis2010，9，： | 1 |
| 16 | Folic acid attenuates hyperhomocysteinemia-induced glomerular damage in rats显示文摘 | Lu Cao Xiaoying Lou Zhaoxia Zou Nana Mou Weikang Wu Xiongqing Huang Hongmei Tan | 2013 | Microvascular Research2013，，： | 1 |
| 17 | Vascu lar fibrosis in atheroselerosis 显示文摘 | LAN Taohua HUANG Xiongqing TAN Hongmei | 2013 | Cardiovase Pathol2013，22，5： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员