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1.
AMETHODFORCALCULATINGKINEMATICPARAMETERS OFHELICOPTERINLOOPANDROLLMANEUVERSCaoYihua;GaoZheng(DepartmentofAircraftEngineering....  相似文献   

2.
ELECTRONICCONTROLOFTURBINEPOWERUNITS¥WangDaobo(DepartmentofScienceandTechnology,NUAA29YudaoStreet,Nanjing210016,P.R.China)Abs...  相似文献   

3.
COMPUTERSIMULATIONOFDIRECTTORQUECONTROLSYSTEM¥HuYuwen;XuYue(DepartmentofAutomaticControl,NUAA29YudaoStreet,Nanjing210016,P.R....  相似文献   

4.
VARIABLESTRUCTUREMODEL-FOLLOWINGADAPTIVECONTROLDESIGNFORROBOTMANIPULATORSZhaoDongbiao;ZhuJianying(DepartmentofMechanicalEngin...  相似文献   

5.
ANEWAPPROACHFORISARTRANSLATIONALMOTIONCOMPENSATIONYinJun;ZhuZhaoda(DepartmentofelectronicEngineering,NUAA29YudaoStreet,Nanjin...  相似文献   

6.
ANOPTICALFIBRESENSORBASEDCUTTINGFORCEMEASURINGDEVICEJinWenling;WangXin(DepartmentofMdchanicalEngineering,NUAA29YudaoStreet,Na...  相似文献   

7.
CALCULATIONOFTHREEDIMENSIONALBOUNDARYLAYEREQUATIONSUSINGDIFFERENTIALQUADRATURE METHODTangDengbin;ChengGuowei(DepartmentofAero...  相似文献   

8.
FASTSOLUTIONOFTURBULENTSEPARATIONBYSTRAW'SMETHODYinJunfei(DepartmentofPowerEngineering,NUAA29YudaoStreet,Nanjing210016,P.R.Ch...  相似文献   

9.
METHODOFEVALUATINGAIRCRAFTTORSIONALAGILITYMETRICUSINGPILOTTRANSFERFUNCTIONMODELHuangPengnian(DepartmentofAerodynamics,NUAA29Y...  相似文献   

10.
OPTIMALDESIGNANDAERODYNAMICCALCULATIONOFWINGCONFIGURATIONOFCIVILAIRCRAFT¥WangLiangyi(DepartmentofAerddynamics,NUAA29YudaoStre...  相似文献   

11.
多层壁瞬态温度分布计算   总被引:3,自引:0,他引:3  
风挡玻璃电防冰和除冰装置、飞机机翼及直升机旋翼电除冰装量都是有内加热的多层壁。这些多层壁中温度分布计算不仅在这些装置的设计计算中是必需的,而且在考虑多层壁的热变形及热应力时也是必要的。本文用数值法对有内加热的多层壁温度分布进行了研究,根据导热微分方程及各种边界条件,用克兰克-尼可尔辛法推出了典型结构的有限差表示式,然后用高斯-赛德迭代法求解线性方程组,得到了可用于多层壁瞬态温度分布的计算软件。本文用该软件对实际的多层金属壁及多层玻璃作了计算。计算表明,计算结果与文[3—5]所得结果相符。本文所述的方法可推广到二维及三维瞬态多层壁温度分布计算,也可用于无内加热层的多层壁温度计算。  相似文献   

12.
从Stratton-Chu公式出发,利用阻抗边界条件,得出阻抗边界条件积分方程,将目标表面分成不同的区域,有些区域用高频解析方法求出其表面电流,有些区域利用矩量法解阻抗边界条件积分方程得表面电流。本文以橄榄体(包括介质涂敷情形)为例,计算其电磁散射特性,混合法计算结果与实测结果或其他方法的计算结果比较吻合。  相似文献   

13.
含孔边裂纹各向异性有限板的二维问题   总被引:1,自引:0,他引:1  
应用边界元法,并结合一种特殊的复变函数基本解,研究了含孔边裂纹的各向异性有限板的应力强度因子修正系数的计算。这种特解边界元法避免了在裂纹附近划分单元,可以获得较好的数值计算精度。通过算例分析,结果表明本方法精度高,运算量小,具有一定的工程应用价值。  相似文献   

14.
工序问题的数学模型   总被引:1,自引:0,他引:1  
本文讨论了加工的次序问题,对于不同的、具有实际意义的问题,我们得到了相应的优化准则,这些准则在实际应用中便于操作,利用这些优化准则得到了加工次序问题的最优的结果。  相似文献   

15.
对带马氏链的线性和非线性系统,经过众多学者近20多年的努力,已取得一系列重要成果。然而,由于马氏链状态逗留时间服从负指数分布,使得这些成果在应用中有很大的局限性。本文首先探讨了位相半马氏过程的性质,然后以位相半马氏过程代替马氏过程,研究风险模型的相关问题,取得了与马氏链相同的研究成果,从而说明了位相半马氏过程在克服由马氏过程带来的局限性中的作用。  相似文献   

16.
推进剂贮箱液体晃动的仿真研究与验证   总被引:1,自引:0,他引:1  
应用CFD软件进行了三维液体晃动仿真计算,得出了全部等效动力学模型参数,仿真结果与解析公式或试验结果符合得很好.还通过仿真计算进行了地面试验的相似准则分析,证明CFD对液体晃动仿真研究是可行的.通过仿真分析,可以获取异形贮箱的晃动特性,辅助和指导地面缩比模型晃动试验的进行.  相似文献   

17.
C C Wang等利用Kosko的双向联想记忆模型(Bidirectional associative memory,BAM),构造了由多个BAM构成的多重BAM(Multi-BAM)决策模型,使之可以应用于多证据推理,获得了Multi-BAM的决策性能。作者在此基础上,通过对各BAM引入不同的权值来模拟各专家不同的权威度,构建了相应的多重加权BAM(Multi-WBAM)模型,证明了该模型在同、  相似文献   

18.
功率谱密度被广泛地应用于分析平稳时间序列,随着现代谱分析技术的发展,经典谱分析技术的缺点得到解决。本文对现代谱分析技术的特点作了论述,利用最大熵谱法分辨率高,特别适用于短数据序列及低信噪比弱信号的特点。通过对几组实测的地脉动响应数据的对比分析,获得了信号的功率话密度(PSD),借助PSD识别出结构的模态频率,而用经典谱方法无法获得。  相似文献   

19.
It is difficult to quantitatively detect defects by using the time domain or frequency domain features of Lamb wave signals due to their dispersion and multimodal characteristics.Therefore,it is important to discover an intrinsical parameter of Lamb waves that could be used as a damage sensitive feature.In this paper,quantitative defect detection in aluminium plates is carried out by means of wavenumber analysis approach.The wavenumber of excited Lamb wave mode is a fixed value,given a frequency,a thickness and material properties of the target plate.When Lamb waves propagate to the structural discontinuity,new wavenumber components are created by abrupt wavefield change.The new wavenumber components can be identified in the frequency-wavenumber domain.To estimate spatially dependent wavenumber values,a short-space two-dimensional Fourier transform(FT)method is presented for processing wavefield data of Lamb waves.The results can be used to determine the location,size and depth of rectangular notch.The analysis techniques are demonstrated using simulation examples of an aluminium plate with a rectangular notch.Then,the wavenumber analysis method is applied to simulation data that are obtained through a range of notch depths and widths.The results are analyzed and rules of the technique with regards to estimating notch depth are determined.Based on simulation results,guidelines for using the technique are developed.Finally,experimental wavefield data are obtained in aluminium plates with rectangular notches by a full noncontact transceiving method,i.e.,laser-laser method.Band-pass filtering combined with continuous wavelet transform is used to extract a certain frequency component from the full laser-induced wavefield with wide band.Shortspace two-dimensional FT method is used for further processing full wavefield data at a certain frequency to estimate spatially dependent wavenumber values.The consistency of simulation and experimental results shows the effectiveness of proposed wavenumber method for quantitative rectangular notch detection.  相似文献   

20.
A nodal discontinuous Galerkin formulation based on Lagrange polynomials basis is used to simulate the acoustic wave propagation. Its dispersion and dissipation properties for the advection equation are investigated by utilizing an eigenvalue analysis. Two test problems of wave propagation with initial disturbance consisting of a Gaussian profile or rectangular pulse are performed. And the performance of the schemes in short, intermediate, and long waves is evaluated. Moreover, numerical results between the nodal discontinuous Galerkin method and fi- nite difference type schemes are compared, which indicate that the numerical solution obtained using nodal discon- tinuous Galerkin method with a pure central flux has obviously high frequency oscillations for initial disturbance consisting of a rectangular pulse, which is the same as those obtained using finite difference type schemes without artificial selective damping. When an upwind flux is adopted, spurious waves are eliminated effectively except for the location of discontinuities. When a limiter is used, the spurious short waves are almost completely removed. Therefore, the quality of the computed solution has improved.  相似文献   

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