共查询到17条相似文献，搜索用时 390 毫秒
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林万涛 《中国科学院研究生院学报》2004,21(3):402-406
针对非线性发展方程的非守恒格式 ,以二维非线性浅水波方程为例 ,给出了计算稳定的必要性条件 .在数值试验的基础上 ,进一步讨论了非线性发展方程非守恒格式与初值之间的关系 .理论分析和数值试验证明 ,非守恒格式的计算稳定性不仅与格式的结构有关 ,而且还由初值及其偏导数的形式所决定 相似文献
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强迫耗散非线性发展方程显式差分格式的计算稳定性 总被引：1，自引：1，他引：1
基于计算准稳定的概念来分析强迫耗散非线性发展方程显式差分格式的计算稳定性,给出强迫耗散非线性大气方程组显式差分格式计算准稳定的判据,为设计强迫耗散非线性大气方程组计算稳定的显式差分格式提供了新的思路和理论依据 相似文献
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王斌 《中国科学院研究生院学报》1988,(2)
本文用待定系数法构造一类平方守恒型差分格式,使得国内外一些常用的在非交错格网上实现的平方守恒型格式均可作为其特例推导出来。此外,还讨论了构造显式完全平方守恒型差分格式的问题。 相似文献
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利用有限差分方法研究了一类非线性Cahn-Hilliard方程,为方程建立了一种三层有限差分格式,讨论了差分解的收敛性和稳定性.虽然格式建立的是一次O(h)边界条件,但是由△2U的定义,可以得到误差次数为O(h2+k2). 相似文献
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这篇文章通过一些典型例子讨论了在用启示性方法时从原偏微分方程推导来的稳定性条件与从差分方程展开式推导来的稳定性条件间的不同点。结果表明，对于部分有限差分方程，在用启示性方法分析其计算稳定性的过程中最好采用从差分方程推导来的展开式以期得到较合理的结果。在文章的另一部分，反证法的运用表明了从启示性方法推导来的稳定性条件并非全都是必要条件，在应用中应引起注意。 相似文献
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固体中冲击波及其一维一阶非线性演化方程数值模拟 总被引：1，自引：0，他引：1
定义固体中的冲击波为冲击波阵面及其后状态物理量发生急剧变化的狭窄区域。利用前人讨论结果进一步探讨了 4种边界输入形式下的冲击波形成距离计算式。分别采用具有二阶精度的显式MacCormack差分格式和MacCormackTVD格式对黏弹性、热弹性以及非均匀性非线性固体介质中一维一阶非线性演化方程进行数值模拟研究,探讨了这些复杂介质中冲击波的形成及演化的基本性质,并较成功地避免了非物理解的产生 相似文献
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Nonlinear two-point boundary value problems have always been difficult to solve. The difficulty is compounded if the problem tends to be inherently unstable. This paper describes an algorithm for solving such sensitive boundary value problems. The procedure is based on a computational method for finding the general solution of systems of ordinary differential equations used in conjunction with the multi-point quasilinearization method of Miele. The method is demonstrated by solving Troesch's problem and a singular perturbation problem. 相似文献
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《Journal of The Franklin Institute》2021,358(18):9890-9908
This paper aims at establishing necessary and sufficient conditions of exponential stability for linear discrete-time systems with multiple delays. Firstly, we introduce a new concept—Lyapunov matrix, and investigate its properties, existence and uniqueness by: (i) characterizing the solution of a boundary value problem of matrix difference equations; and (ii) constructing complete type Lyapunov–Krasovskii functionals with pre-specified forward difference. Secondly, a new constructive analysis methodology, named Lyapunov matrix approach, is proposed to establish necessary and sufficient exponential stability conditions for discrete-time systems with multiple delays. Finally, two numerical examples are presented to illustrate the effectiveness of the theoretical results. It is worth emphasizing that, from a view of computation, the Lyapunov matrix approach proposed here is concerned with three key steps: (i) solve a systems of linear equations; (ii) check whether a constant matrix is of full-column-rank, and (iii) judge whether a constant matrix is positive definite. All of these can be easily realized by using the tool software—MATLAB. 相似文献
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A.S.C. Sinha 《Journal of The Franklin Institute》1974,297(4):287-292
The problem of stability properties for the solutions of nonlinear difference equations is considered. The approach used is to study the behavior of the solutions of nonlinear difference equations with respect to solutions of a nonlinear difference equation. This is a more general setting than the comparison principle in which the comparison equation is a linear difference equation.The principal technique employed is an extension of Liapunov's direct method. A series of theorems is obtained yielding criteria for the behavior of solutions in terms of existence of the Liapunov-type function with appropriate properties. 相似文献
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研究了双极(非线性)Schr(o)dinger-Poisson系统和拟线性Schr(o)dinger-Poisson方程,得到了双极Schr(o)dinger-Poisson系统的整体适定性及其修正散射理论,以及单位方体上的具有Dirichlet边值条件的拟线性Schr(o)dinger-Poisson方程的初边值问题整体解的存在唯一性. 相似文献
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研究了双极(非线性) Schr"odinger-Poisson 系统和 拟线性Schr"odinger-Poisson 方程, 得到了双极 Schr"odinger-Poisson 系统的整体适定性及其修正散射理论, 以及单位方体上的具有 Dirichlet 边值条件的 拟线性Schr"odinger-Poisson 方程的初边值问题整体解的存在唯一性. 相似文献
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《Journal of The Franklin Institute》2022,359(7):3238-3290
The space debris removal system (SDRS) of tethered space tug is modelled as a cable dragged flexible spacecraft. The main goal of this paper is to develop a dynamic modeling approach for mode characteristics analysis and forced vibration analysis of the planar motion of a cable dragged flexible spacecraft. Solar arrays of the spacecraft are modelled as multi-beams connected by joints with additional rotating spring where the nonlinear stiffness, damping and friction are considered. Using the Global mode method (GMM), a novel analytical and low-dimensional nonlinear dynamic model is developed for vibration analysis of SDRS to enhance the design capacity for better fulfillment of space tasks. The linear and nonlinear partial differential equations that governing transverse vibration of solar arrays, transverse and longitudinal vibrations of cable are derived, along with the matching and boundary conditions. The natural frequencies and analytical global mode shapes of SDRS are determined, and orthogonality relations of the global mode shapes are established. Dynamical equations of the system are truncated to a set of ordinary differential equations with multiple-DOF. The validity of the method is verified by comparing the natural frequencies obtained from the characteristic equation with those obtained from FEM. Interesting mode localization and mode shift phenomena are observed in mode analysis. Dynamic responses of the system excitated by fluctuation of attitude control torque and short-time attitude control torque are worked out, respectively. Nonlinear behaviors are observed such as hardening, jump and super-harmonic resonances. Residual vibration of the overall system with considering the varous values of nonlinear stiffness, damping coefficient and friction coefficient has shown that the nonlinearity of joints has a great influence on the vibration of the overall system. 相似文献
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C.M. Leech 《Journal of The Franklin Institute》1980,309(2):65-90
The equations of motion of a rigid body are developed in body fixed axes; the aerodynamic forces and moments are expressed as elements of a Taylor series in the six kinematic rates (body velocities and spins). Stability is approached firstly by forcing Jacobi elliptic functions into the equations of motion; stability criteria follow either as unconditional system stability or as a conditional criterion dependent upon the launch conditions. Stability is also considered by way of the motion invariants and their relation to kinetic energy. Three basic systems are considered and numerical integration gives detailed system responses; pertubation of the various aerodynamic effects changes the responses and the stability from unconditional stability to instability or conditional stability. 相似文献