1998 Vol. 24, No. 6

Display Method:
Implicit Schemes for Numerical Simulations of Hypersonic Nonequilibrium Flows
Wu Songping, Lu Ye, Zheng Bo
1998, 24(6): 625-628.
Abstract:
Two forms of implicit TVD schemes are proposed in this paper for the simulation of nonequilibrium flows past hypersonic re-entry vehicle, which are derived from the diagonal form of an approximate-factorization algorithm and lower-upper scheme applied to the implicit part of Harten-Yee's TVD scheme ...
Implicit Flux-Vector-Splitting Solution of Three Dimensional Parabolic Navier-Stokes Equations
Liu Yu, Zhang Zhenpeng
1998, 24(6): 629-632.
Abstract:
By the use of implicit flux-vector-splitting method, three-dimensional dimensionless conservative parabolic navier-stokes equation is solved in general curved coordinates system. The code developed can be used to solve the three-dimensional flow field with comparatively complex boundary such as the ...
Analytical Solutions of Linearly Elastic Impact of Beams
Xing Yufeng
1998, 24(6): 633-637.
Abstract:
According to the elastic impact problems of structures are considered as initial value problems of the integrated impact structural systems,and the analytical solutions of a particle and a rod impacting laterally with a simply-supported beam are given. The dynamical responses of the above-mentioned ...
Nonlinear Behavior of Separated Shear Layer of a Blunt Circular Cylinder
Dong Yufei
1998, 24(6): 638-641.
Abstract:
Dynamical evolution process of separated shear layer of a blunt circular cylinder,and nonlinear interaction between separated shear layer and acoustic forcing have been experimentally investigated. The researches demonstrate, in unexcited state, there exists the subharmonic phenomenon, which implies...
Grid Generation Technique of Complex Configurations and its Applications
Zhang Zhengke, Zhu Ziqiang, Zhuang Fenggan
1998, 24(6): 642-645.
Abstract:
A multiblock structured grid generation system for complex practical aircraft is presented and applied in the grid generation of a twin-tail fighter. A vectorized polynomial of degree 3 is used to generate grid on the interface of adjacent blocks. The volume grid in each block is generated by solvin...
Investigation into Tensile Mechanical Propertiesof PUR Foam Plastics
Lu Zixing, Kou Changhe, Li Huaixiang
1998, 24(6): 646-649.
Abstract:
The tensile mechanical properties of PUR foam plastics as well as its strain rate effect and temperature effect were investigated by means of tensile experiments. The experimental results show that the strain rate effect of PUR foam plastics is not obvious, but its temperature effect is quite obviou...
Research on Optimal Pointing Maneuvers of Post Stall Aircraft
Zhang Shuguang, Sun Jinbiao
1998, 24(6): 650-653.
Abstract:
A terminal condition is put forward based on nonlinear point-mass aircraft dynamics, under which the given movable target shall be pointed. A numerical procedure on optimization of minimum-time pointing maneuvers is then established, in which the conjugate gradient method is employed to search for t...
Effects of Stretching Conditions on Forming Quality of Mirror Skins
Wan Min, Zhou Xianbin, Li Xiaoxing, Wu Hui
1998, 24(6): 654-657.
Abstract:
On the basis of full consideration of the slip band appearing and the shape fixability of forming parts,reasonable conditions in stretch forming of airplane mirror skins have been determined by means of analysis of the effects of stretching velocity, geometrical dimensions of blank, geometrical para...
Quasi-Quantitative Study on Organizational Decisionand Organizational Structure
Fang Weiguo, Zhou Hong, Zheng Yun
1998, 24(6): 658-661.
Abstract:
Directed towards the characteristics of uncertain environment the modern organization faces, a general mathematical model of organizational decision-making is established. The organizational structure and its value are investigated in the views of decision-making and information communication. Integ...
Study on Information Sharing Mechanism of Organizational Decision Making
Fang Weiguo, Zhou Hong
1998, 24(6): 662-666.
Abstract:
By feat of category theory, the impact mechanism of actualization consequences of decision alternatives shared among decision units on improving organizational decision-making was explored. The concept of information-sharing was presented. Then, organizational decision-making was formulated as a cat...
Tentative Research for Chaotic Fatigue
Xiong Junjiang, Wu Zhe, Gao Zhentong
1998, 24(6): 667-670.
Abstract:
The bifurcation and chaos theory of dynamic system is introduced to study the sudden change of fatigue behavior. A micro-model to describe the fatigue damage dynamic system is proposed on the basis of physical mechanics. The local saddle-node, Hopf bifurcations and global bifurcations of this fatigu...
Numerical Simulation of Chemical Reacting Flow in H2/O2 Rocket Engine Thrust Chamber
Cai Guobiao, Zhang Huazhao, Zhuang Fenggan
1998, 24(6): 671-675.
Abstract:
The viscous chemical reacting flow in the hydrogen-oxygen rocket engine chamber and nozzle is simulated by using loosely coupled point-implicit MacCormack scheme. In the numerical simulation the combustion process is modeled by using a 6-specis, 8-step finite-rate chemical reaction model, and the Ba...
Method of State Observer Design and Fault Detection
Wen Xin, Wang Qing, Qian Fang, Zhang Hongyue
1998, 24(6): 676-679.
Abstract:
Radial Gaussian function networks based fuzzy systems with adaptive capability,are applied to the state estimation and fault detection of nonlinear time-varying systems .In order to extract fuzzy IF-THEN rules from input and output sample data through learning,the Gaussian function is employed to re...
Theoretical Model for Dissipation-Rate Budgets in Near-WallRegion of a Turbulent Boundary Layer
Lu Lipeng, Chen Maozhang
1998, 24(6): 680-683.
Abstract:
Based on the linear hydrodynamic stability theory, a 3-D theoretical model is proposed for the turbulent fluctuations in near-wall region of a turbulent boundary layer. In accordance with the theoretical model, budgets of the the dissipation-rate of turbulent kinetic energy are calculated and its pr...
Decentralized Fuzzy Variable-Structure Control for Manipulators
Wang Qing, Wen Xin, Zhang Minglian
1998, 24(6): 684-687.
Abstract:
A decentralized fuzzy variable-structure control is presented for trajectory tracking of robot manipulators. Considering the overall system as a set of linear subsystems with nonlinear uncertainties and interconnections, the tracking problem is tackled by decentralized control method. The proposed c...
Prediction of Simulant Formability by Computer
Wang Lidong, Hu Shiguang
1998, 24(6): 688-691.
Abstract:
The relationship between the fundamental formability (tension, plane-strain, etc) and the simulant formability (deep-drawing, cupping, hole-expansion, fuki's cup) was studied by means of artificial neural network. Based on a lot of experimental data and the back-propagation algorithm, a B-P neural n...
Research on the Characteristic of Optimal FlightRoute in the Terminal Area
Xue Lilin, Wang Weihong, Gao Jinyuan
1998, 24(6): 692-694.
Abstract:
A method named multi-times optimization is presented to solve the multi-specification optimization problem,which is difficult to solve using the variational optimal theory.In the method several demands are reduced to some sub-tasks.In every subtask a demand that can not be transformed into bound con...
All Digital DSP Based Closed-Loop Fiber Optic Gyroscope
Zhang Chunxi, Song Ningfang, Du Xinzheng, Zhang Weixu
1998, 24(6): 695-698.
Abstract:
An all digital closed-loop fiber optic gyroscope (FOG) using digital signal processor (DSP) technique is presented.A multifunction integrated optic circuit (MIOC) is used, with square wave for biasing modulation and digital phase ramp for feed back. The design of signal detector,digital demodulator,...
Virtual Enterprise and Information Sharing Management in Virtual Enterprise
Yan Kaitao, Deng Jiati
1998, 24(6): 699-703.
Abstract:
The concept and characteristics of virtual enterprise are discussed and an integrated framework is proposed as well. The emphasis is on the analysis of requirement and the presentation of a general approach for information sharing management in virtual enterprise. This approach consists of sharing m...
Analysis of Axial-Flow Compressors Stall in Uniform and Distorted Inlet Flow
Zhang Mingchuan, Zhang Jin, Tang Diyi
1998, 24(6): 704-706.
Abstract:
Using a row-to-row two-dimension nonlinear model,rotating stall parameters in a single rotor compressor are simulated, and compared well with the experimental data. The effects of inlet circumferential static distortion on the rotating stall in an one-stage compressor are investigated. Results show ...
Singularly Perturbed Midcoursr Guidance Law for Quickly Ascending Air-to-Ground Missiles
Fu Li, Fan Yaozu
1998, 24(6): 707-710.
Abstract:
Based on optimal control theory and singularly perturbed theory,a singularly perturbed midcourse guidance law that guarantees air-to-ground missiles to ascent quickly is proposed.This new guidance law is a composite control law consisting of three parts:optimal climbing control using variable weight...
Study on Transient of Automata System for Liquid Rocket Engine
Zhang Lihui, Zhang Zhenpeng, В.Н.Гладкова
1998, 24(6): 711-713.
Abstract:
A physical model of the automatic control system of a pump-fed Liquid Rocket Engine (LRE) is constructed, for which a nonlinear mathematical model is built. Considering the interfering modalities probably happening and input with step form, the dynamic characteristic in each interfering status is si...
Approach to Dependability Modelling for Effectiveness Analysis of Ground Vehicle System
Wang Wuhong, Yang Weimin
1998, 24(6): 714-717.
Abstract:
The dependability analysis of every mission period within every mission profile for repairable system is essential for the quantitative evaluation of system effectiveness and for designing effective system. In this paper, the mission succession probability is chosen as measurement of dependability w...
ENO Finite Volume Method For Unstructured Triangular Mesh
Song Songhe, Chen Maozhang
1998, 24(6): 718-721.
Abstract:
A third order ENO finite volume method for hyperbolic conservation laws on unstructured triangular mesh is introduced.In order to obtain the third order accuracy on spatial discretization,a weighted quadratic interpolation is constructed on every triangular mesh.Two point Gauss quadrature formula is...
New Modified Adaptive Extended Kalman Filterof DR System for Land Vehicle Navigation
Fang Jiancheng, Shen Gongxun, Wan Dejun
1998, 24(6): 722-725.
Abstract:
A new observation equation of the dead reckoning (DR) system for land vehicle navigation is presented, and a modified adaptive extended Kalman filter and its filtering algorithm for the DR system are proposed. By consideration of Markov process component in the random drift of rate gyros, and applic...
Basic Operations in the Language Processing
Guo Honglei, Li Wei
1998, 24(6): 726-729.
Abstract:
The basic operations in the language processing are classified from viewpoint of the entity and the attribute respectively, and two sets of basic operations , i.e., Attribute-derived operation set and Entity alternation operation set, are defined systematically . The attribute-derived operation set ...
Study on the Hydromechanical Behavior of Rubber Particles in Vibrated Fluidized Bed
Wang Xiaoxin Yuan Xiugan
1998, 24(6): 730-733.
Abstract:
For the sake of investigating hydromechanical behavior of particles in vibrated fluidized bed, this paper studies the effects of vibration intensity, height of bed and gas velocity on pressure drop through a model vibrated fluidized bed equipment with rubber particles as sample materials. The variat...
Effects of the Microstructure of γ-TiAl Alloys on the Creep Behavior
Lin Jianguo, Zhang Yonggang, Chen Changqi
1998, 24(6): 734-737.
Abstract:
The relationship between microstructure and creep behavior of γ-TiAl alloys was analyzed and discussed, and the effect of the orientation of lamellar boundaries with respect to loading axis on the creep behavior of TiAl alloy with fully lamellar structure was studied by using TiAl PST crystals. It i...
Applying DSG Method to Part Model Decomposition
Yu Yong, Tang Rongxi
1998, 24(6): 738-741.
Abstract:
Part machining can be imagined as a modeling procedure within which only a series of Boolean subtracting between father body and child body happen. To obtain such a series of subtracting body, Destructive Solid Geometry(DSG) theory is applied to orderly decompose the part design model into correspon...
D-K Iteration Algorithm Based on Graphical User Interface
He Yufen, Xiong Zhang, Liu Xudong
1998, 24(6): 742-746.
Abstract:
Based on the μ synthesis of the pitch axis controller of a fighter, the standard D-K iteration algorithm is presented. The command-line driven D-K iteration algorithm is not manipulated easily by control designers due to the complexity of the algorithm. In order to keep the algorithm well informed a...
Study of Fatigue Strength Condition for Non-Symmetrical Circulation
Yun Chao, Zong Guanghua, Jin Shuda
1998, 24(6): 747-749.
Abstract:
The fatigue strength condition of component parts under non-symmetrical circulation is analysed for the tranditional design of mechanism in order to infer an expression about the fatigue strength condition. In terms of material mechanics, the working safe coefficient of components under the same cir...