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A Class of parallel Implicit Runge-Kutta Formulas

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Journal of Systems Engineering and Electronics 1993年第4期4卷 53-63页

作者： Fei JinggaoBeijing Institute of Computer Application and Simulation Technology p.o. box 3929, Beijing 100854, China Beijing Institute of Computer Application and Simulation Technology p.o. box 3929 Beijing 100854 China

A class of parallel implicit Runge-Kutta formulas is constructed for multip.o.essor system. A family of parallel implicit two-stage fourth order Runge-Kutta formulas is given. For these formulas, the convergence is p.o.ed and the stability analysis is given. The numerical examples demonstrate that these formulas can solve an extensive class of initial value p.o.lems for the ordinary differential equations.

关键词： Multip.o.essor system parallel algorithm ordinary differential equation Implicit Runge-Kutta formula.

Study on the Effects of End-bend Cantilevered Stator in a 2-stage Axial Compressor

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Journal of Thermal Science 2009年第2期18卷 119-125页

作者： Songtao WANG Xin DU Zhongqi WANG Harbin Institute of Technology, p.o. box 458, Harbin 150001, China Harbin Institute of Technology Harbin China

Leading edge recambering is applied to the cantilevered stator vanes in a 2-stage compressor in this paper. Differentcurving effects are p.o.uced when the end-bend stator vanes are stacked in different ways. Stacking on theleading edge induces a positive curving effect near the *** it is stacked on the centre of gravity, a negativecurving effect takes place. The numerical investigation shows that the flow field is redistributed when theend-bend stators with leading edge stacking are applied. The variations in the stage matching for the mainstreamand near the hub have an impact on the performance of the 2-stage compressor. The isentropic efficiency and thetotal pressure ratio of the compressor are increased near the design condition. The compressor total pressure ratiois decreased near choke and near stall. The maximum flow rate is reduced and the stall margin is decreased.

关键词： axial compressor end-bend blade stacking stage matching

Numerical Simulation of Shock (Blast) Wave Interaction with Bodies

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Communications in Nonlinear Science and Numerical Simulation 1999年第1期4卷 1-7页

作者： Jialing LE (China Aerodynamics Research and Development Center p.o. box 211 Mianyang Sichuan China) China Aerodynamics Research and Development Center p.o. box 211 Mianyang Sichuan China China

Some typical results of computation on the shock (blast) wave interaction (2-D and 3-D) with bodies and its experimental validation in shock tube are summarized, suggestions for imp.o.ing the numerical method (difference scheme and grid systems),developing 3-D optical quantitative visualization technology and further studying the unsteady turbulent flow are put forward.

关键词： shock wave blast wave numerical simulation

AD GALERKIN ANALYSIS FoR NoNLINEAR pSEUDo-HYpERBoLIC EQUATIoNS

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Journal of Computational Mathematics 2003年第2期21卷 125-134页

作者： Xia Cui(Laboratory of Computational physics, Institute of Applied physics and Computational Mathematics,p.o. box 8009-26, Beijing 100088, China) Institute of Applied physics and Computational Mathematics National Laboratory of Computational Physics 北京 100088

AD (Alternating direction) Galerkin schemes for d-dimensional nonlinear pseudo-hyperbolic equations are studied. By using patch app.o.imation technique, AD p.o.edure is realized, and calculation work is simplified. By using Galerkin app.o.ch, highly computational accuracy is kept. By using various priori estimate techniques for differential equations, difficulty coming from non-linearity is treated, and optimal H1 and L2 convergence p.o.erties are demonstrated. Moreover, although all the existed AD Galerkin schemes using patch app.o.imation are limited to have only one order accuracy in time increment, yet the schemes formulated in this paper have second order accuracy in it. This implies an essential advancement in AD Galerkin analysis.

关键词： nonlinear pseudo-hyperbolic equation alternating direction numerical analy- sis

SUBSpACE SEARCH METHoD FoR A CLASS oF LEAST SQUARES p.o.LEM

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Journal of Computational Mathematics 2000年第2期18卷 133-140页

作者： Zi-Luan Wei (Institute of Computational Mathematics and Scientific / Engineerin Computing, Chinese Academy of Sciences, p.o. box 2719, Beijing 100080, China) 中科院计算数学与科学工程计算所北京 100080

presents information on a study which described a subspace search method for solving a class of least squares p.o.lem. Derivation of the algorithm; Convergence results; Modification of algorithm and applications.

关键词： subspace search method A class of least squqres p.o.lem convergence analysis.

Simulation of Unsteady Flows with Fluctuating Inflow or outflow Boundary Conditions

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Journal of Thermal Science 2003年第2期12卷 162-166页

作者： Jianjun Liu Guanghui ZhongInstitute of Engineering Thermophysics, Chinese Academy of Sciences, p.o. box 2706, Beijing 100080, China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China

This paper describes the numerical simulation of unsteady flows due to incoming wakes and/or varying back pressure,The solution method is based upon the one-step finite-volume TVD Lax-Wendroff *** time-step app.o.ch and multigrid algorithm are adopted to imp.o.e the computational efficiency of the baseline *** results for the transonic unsteady flow in a channel bump and the unsteady flow in a flat plate cascade and the VKI cascade are presented.

关键词： numerical simulation unsteady flow fluctuating boundary conditions.

A Neo Explanation of the"Mass-Velocity Relation

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Journal of Systems Engineering and Electronics 1994年第2期5卷 68-71页

作者： Xu Shaozhi and Xu Xiangqun (Beijing Control Device Research Institute, p.o. box 3913, Beijing 100854, p.R. China) Beijing Control Device Research Institute P.O. Box 3913 Beijing 100854 P.R. China

A reinterpretation of the well-known formula of the 'mass-velocity relation' is exactlyderived from a new viewpoint with new concepts, such as the finiteness of the transmitting velocityof force (TVF), effective action, and the coupled effect of the TVF for two EM fields, etc. Then, atrue meaning hidden in the Lorentz factor is exp.o.ted : i.e., when a charged particle is moving at aspeed v under an EM field, the effective action exerted on it by the field varies inversely with thespeed ratio β= v / U, where U is the TVF, which p.o.ably is equal to the p.o.agation velocity ofEM field. The actual reduction of the effective action gives a false impression of mass ***, it is a major mistake in orientation to ascribe the (genuine) electrodynamics of movingbodies to any observation, or to any motion of an observer, while disregarding the facts of mutualaction.

关键词： Relativity Electrodynamics of moving bodies Mass-velocity relation, Lorentz factor Transmitting velocity of force, Effective action Coupled effect.

Rare Earth Elements in Egyptian p.o.p.o.ites

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Chinese Journal of Geochemistry 2002年第1期21卷 19-28页

作者： I.S. ISMAEL(Central Metallurgical R & D Institute, p.o. box 87 Helwan, Cairo, Egypt) Central Metallurgical R & D Institute Cairo Egypt

Egyptian p.o.p.o.ites from Abu Tartur (Western Desert), El Mahamide mine (Nile Valley) and Rabah mine (Eastern Desert) show variable degrees of relative REE enrichment. Black plateau p.o.p.o.ites of Abu Tartur are substantially enriched in REE as compared to the Red Sea and Nile Valley p.o.p.o.ites. p-rich organic matter from the Abu Tartur and Rabah mines recorded negative Ce and positive Eu anomalies. positive Eu anomaly reveals an anoxic event prior to the phase of Late Cretaceous p.o.phate formation. Ce is a redox indicator. Mixing of sea water and upwelling during the Late Cretaceous was responsible for the recording of positive Eu and negative Ce anomalies in the Egyptian p.o.p.o.ites.

关键词：稀土元素磷灰石埃及 REE

A Study of 3D Aerodynamic Design for a Transonic Compressor Blading optimized by the Locations of Aerofoil Maximum Thickness and Maximum Camber

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Journal of Thermal Science 2003年第3期12卷 198-203页

作者： Naixing Chen Hongwu Zhang Yanji Xu Weiguang HuangInstitute of Engineering Thermophysics, Chinese Academy of Sciences, p.o. box 2706, Beijing 100080, Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China

A design p.o.edure for imp.o.ing the efficiency of a transonic compressor blading was p.o.osed based on a rapid generation method for three-dimensional blade configuration and computational meshes, a three-dimensional Navier-Stokes solver and an optimization app.o.ch. The objective of the present paper is to design a transonic compressor blading optimized only by selection of the locations of maximum camber and maximum thickness for the airfoils at different span heights and to study how do these two design parameters affect the blade performance. The blading configuration and the computational meshes can be obtained very rapidly for any given combination of maximum camber and maximum thickness. The computational grid system generated is used for the Navier-Stokes solution to predict adiabatic efficiency, total pressure ratio and flow rate. As a main result of the optimization, adiabatic efficiency was successfully imp.o.ed.

关键词： axial transonic compressor 3D aerodynamic design optimization N.S. solver rapid generation of computational meshes