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Stability of Difference Schemes with Intrinsic Parallelism for Quasilinear Parabolic Systems 被引量:10
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作者 Zhou Yulin and Yuan GuangweiLaboratory of Computational PhysicsCentre for Nonlinear Studies(Institute of Applied Physics and Computational MathematicsP. O. Box 8009, Boiling, 100088, China) 《Wuhan University Journal of Natural Sciences》 CAS 1996年第Z1期579-592,共14页
In this paper, the first boundary problem of quasilinear parabolic system of second order is studied by the finite difference method with intrinsic parallelism. for the problem, the stability of the difference schemes... In this paper, the first boundary problem of quasilinear parabolic system of second order is studied by the finite difference method with intrinsic parallelism. for the problem, the stability of the difference schemes with intrinsic parallelism are justified in the sense of the continuous dependence of the discrete vector solution of the difference schemes on the discrete data of the original problem, without assuming the existence of the smooth solutions for the origillal problem. 展开更多
关键词 difference scheme Intrinsic parallelism Quasilinear 'parabolic systems Stability.
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A Class of Stable Difference Schemes For Linear Elliptic PDEs And Their Asynchronous Parallel Computation
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作者 Wen Shangmeng Li Xiaomei(Dept. of Compactor, Changsha I.nstitutc of TechnologyChangsha, Hunan 410073, P.R. of China) 《Wuhan University Journal of Natural Sciences》 CAS 1996年第Z1期553-556,共4页
This paper improves and generalizes the two difference schemes presented in paper [1] and gives a new difference scheme for second order linear elliptic partial differential equations, its difference matrix is a matri... This paper improves and generalizes the two difference schemes presented in paper [1] and gives a new difference scheme for second order linear elliptic partial differential equations, its difference matrix is a matrix and because of the stability of the M-matrix, it is convergent by the asynchronous iterative method on multiprocessors. Then this paper gives a class of differeifce schemes for linear elliptic PDEs so that their difference matrixes are all M-matrixes and their asynchronous parallel computation are convergent. 展开更多
关键词 difference scheme partial differential equation parallel computation.
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可再生能源电解水制氢电源并联方案研究
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作者 章小卫 苏星宇 +1 位作者 周京华 孟祥飞 《太阳能学报》 北大核心 2025年第1期353-362,共10页
利用可再生能源发电进行电解水制氢是实现可再生能源的100%消纳和氢气全绿制取的重要途经。作为衔接可再生能源发电母线和质子交换膜电解槽的中间环节,单个制氢电源功率等级低,不能满足大规模可再生能源消纳和大功率制氢,因此需采用制... 利用可再生能源发电进行电解水制氢是实现可再生能源的100%消纳和氢气全绿制取的重要途经。作为衔接可再生能源发电母线和质子交换膜电解槽的中间环节,单个制氢电源功率等级低,不能满足大规模可再生能源消纳和大功率制氢,因此需采用制氢电源的模块化并联方法,但模块化并联时存在模块间不均流问题。针对多个制氢电源并联时的不均流问题,提出基于三相交错并联LLC结构的制氢电源并联方案。首先,推导了多个制氢电源并联等效电路,从阻抗角度入手,得到模块间谐振参数差异是不均流的主要原因。然后,利用虚拟阻抗调整等效阻抗,从而实现模块间均流。最后,搭建仿真模型和一台两个6 kW模块化实验样机,验证了所提并联方案的合理性和可行性。 展开更多
关键词 可再生能源发电 电解水制氢 制氢电源并联方案 谐振参数差异 虚拟阻抗
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General difference schemes with intrinsic parallelism for nonlinear parabolic systems 被引量:7
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作者 周毓麟 袁光伟 《Science China Mathematics》 SCIE 1997年第4期357-365,共9页
The boundary value problem for nonlinear parabolic system is solved by the finite difference method with intrinsic parallelism. The existence of the discrete vector solution for the general finite difference schemes w... The boundary value problem for nonlinear parabolic system is solved by the finite difference method with intrinsic parallelism. The existence of the discrete vector solution for the general finite difference schemes with intrinsic parallelism is proved by the fixed-point technique in finite-dimensional Euclidean space. The convergence and stability theorems of the discrete vector solutions of the nonlinear difference system with intrinsic parallelism are proved. The limitation vector function is just the unique generalized solution of the original problem for the parabolic system. 展开更多
关键词 difference scheme INTRINSIC parallelISM nonlinear PARABOLIC system CONVERGENCE stability.
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GENERAL DIFFERENCE SCHEMES WITH INTRINSICPARALLELISM FOR SEMILINEAR PARABOLIC SYSTEMS OFDIVERGENCE TYPE 被引量:8
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作者 Yu-lin Zhou Guang-wei Yuan(Laboratory of Computational Physics, Center of Nonlinear Studies, Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088, China) 《Journal of Computational Mathematics》 SCIE EI CSCD 1999年第4期337-352,共16页
In this paper the general finite difference schemes with intrinsic parallelism for the boundary value problem of the semilinear parabolic system of divergence type with bounded coefficients are constructed, and the ex... In this paper the general finite difference schemes with intrinsic parallelism for the boundary value problem of the semilinear parabolic system of divergence type with bounded coefficients are constructed, and the existence and uniqueness of the difference solution for the general schemes are proved. And the convergence of the solutions of the difference schemes to the generalized solution of the original boundary value problem of the semilinear parabolic system is obtained. The multidimensional problems are also studied. 展开更多
关键词 difference scheme intrinsic parallelism semilinear parabolic system CONVERGENCE
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Parallel difference schemes with interface extrapolation terms for quasi-linear parabolic systems 被引量:6
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作者 Guang-wei YUAN Xu-deng HANG Zhi-qiang SHENG 《Science China Mathematics》 SCIE 2007年第2期253-275,共23页
In this paper some new parallel difference schemes with interface extrapolation terms for a quasi-linear parabolic system of equations are constructed. Two types of time extrapolations are proposed to give the interfa... In this paper some new parallel difference schemes with interface extrapolation terms for a quasi-linear parabolic system of equations are constructed. Two types of time extrapolations are proposed to give the interface values on the interface of sub-domains or the values adjacent to the interface points, so that the unconditional stable parallel schemes with the second accuracy are formed. Without assuming heuristically that the original boundary value problem has the unique smooth vector solution, the existence and uniqueness of the discrete vector solutions of the parallel difference schemes constructed are proved. Moreover the unconditional stability of the parallel difference schemes is justified in the sense of the continuous dependence of the discrete vector solution of the schemes on the discrete known data of the original problems in the discrete W2(2,1) (Q△) norms. Finally the convergence of the discrete vector solutions of the parallel difference schemes with interface extrapolation terms to the unique generalized solution of the original quasi-linear parabolic problem is proved. Numerical results are presented to show the good performance of the parallel schemes, including the unconditional stability, the second accuracy and the high parallelism. 展开更多
关键词 parallel difference scheme interface extrapolation quasi-linear parabolic system unconditional stability convergence 65M06 65M12 65M55
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THE UNCONDITIONAL STABILITY OF PARALLEL DIFFERENCE SCHEMES WITH SECOND ORDER CONVERGENCE FOR NONLINEAR PARABOLIC SYSTEM 被引量:10
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作者 Yuan Guangwei Sheng Zhiqiang Hang Xudeng 《Journal of Partial Differential Equations》 2007年第1期45-64,共20页
For solving nonlinear parabolic equation on massive parallel computers, the construction of parallel difference schemes with simple design, high parallelism and unconditional stability and second order global accuracy... For solving nonlinear parabolic equation on massive parallel computers, the construction of parallel difference schemes with simple design, high parallelism and unconditional stability and second order global accuracy in space, has long been desired. In the present work, a new kind of general parallel difference schemes for the nonlinear parabolic system is proposed. The general parallel difference schemes include, among others, two new parallel schemes. In one of them, to obtain the interface values on the interface of sub-domains an explicit scheme of Jacobian type is employed, and then the fully implicit scheme is used in the sub-domains. Here, in the explicit scheme of Jacobian type, the values at the points being adjacent to the interface points are taken as the linear combination of values of previous two time layers at the adjoining points of the inner interface. For the construction of another new parallel difference scheme, the main procedure is as follows. Firstly the linear combination of values of previous two time layers at the interface points among the sub-domains is used as the (Dirichlet) boundary condition for solving the sub-domain problems. Then the values in the sub-domains are calculated by the fully implicit scheme. Finally the interface values are computed by the fully implicit scheme, and in fact these calculations of the last step are explicit since the values adjacent to the interface points have been obtained in the previous step. The existence, uniqueness, unconditional stability and the second order accuracy of the discrete vector solutions for the parallel difference schemes are proved. Numerical results are presented to examine the stability, accuracy and parallelism of the parallel schemes. 展开更多
关键词 parallel difference scheme nonlinear parabolic system unconditional stability second order convergence.
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Difference schemes with intrinsic parallelism for quasi-linear parabolic systems 被引量:2
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作者 周毓麟 《Science China Mathematics》 SCIE 1997年第3期270-278,共9页
The boundary value problem for quasi-linear parabolic system is solved by the finite difference method with intrinsic parallelism The existence and uniqueness and convergence theorems of the discrete vector solu tions... The boundary value problem for quasi-linear parabolic system is solved by the finite difference method with intrinsic parallelism The existence and uniqueness and convergence theorems of the discrete vector solu tions of the nonlinear difference system with intrinsic parallelism are proved The limiting vector function is just the unique generalized solution of the original problem for the parabolic system 展开更多
关键词 difference scheme INTRINSIC parallelISM QUASI-LINEAR PARABOLIC system.
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Alternating segment explicit-implicit scheme for nonlinear third-order KdV equation 被引量:1
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作者 曲富丽 王文洽 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第7期973-980,共8页
A group of asymmetric difference schemes to approach the Korteweg-de Vries (KdV) equation is given here. According to such schemes, the full explicit difference scheme and the full implicit one, an alternating segme... A group of asymmetric difference schemes to approach the Korteweg-de Vries (KdV) equation is given here. According to such schemes, the full explicit difference scheme and the full implicit one, an alternating segment explicit-implicit difference scheme for solving the KdV equation is constructed. The scheme is linear unconditionally stable by the analysis of linearization procedure, and is used directly on the parallel computer. The numerical experiments show that the method has high accuracy. 展开更多
关键词 KdV equation intrinsic parallelism alternating segment explicit-implicit difference scheme unconditionally linear stable
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The unconditional stable and convergent difference methods with intrinsic parallelism for quasilinear parabolic systems 被引量:6
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作者 ZHOU Yulin YUAN Guangwei SHEN Longjun Laboratory of Computational Physics, Center of Nonlinear Studies, Institute of Applied Physics and Computational Mathematics, Beijing 100088, China 《Science China Mathematics》 SCIE 2004年第3期453-472,共20页
A kind of the general finite difference schemes with intrinsic parallelism for the boundary value problem of the quasilinear parabolic system is studied without assuming heuristically that the original boundary value ... A kind of the general finite difference schemes with intrinsic parallelism for the boundary value problem of the quasilinear parabolic system is studied without assuming heuristically that the original boundary value problem has the unique smooth vector solution. By the method of a priori estimation of the discrete solutions of the nonlinear difference systems, and the interpolation formulas of the various norms of the discrete functions and the fixed-point technique in finite dimensional Euclidean space, the existence and uniqueness of the discrete vector solutions of the nonlinear difference system with intrinsic parallelism are proved. Moreover the unconditional stability of the general finite difference schemes with intrinsic parallelism is justified in the sense of the continuous dependence of the discrete vector solution of the difference schemes on the discrete data of the original problems in the discrete W 2 (2,1) norms. Finally the convergence of the discrete vector solutions of the certain difference schemes with intrinsic parallelism to the unique generalized solution of the original quasilinear parabolic problem is proved. 展开更多
关键词 difference scheme INTRINSIC parallelism quasilinear PARABOLIC system convergence stability.
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THE UNCONDITIONAL STABLE DIFFERENCE METHODS WITH INTRINSIC PARALLELISM FOR TWO DIMENSIONAL SEMILINEAR PARABOLIC SYSTEMS 被引量:5
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作者 Guangwei Yuanf Longjun Shen(National Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing, 100088, China) 《Journal of Computational Mathematics》 SCIE CSCD 2003年第1期63-70,共8页
In this paper we are going to discuss the difference schemes with intrinsic parallelism for the boundary value problem of the two dimensional semilinear parabolic systems. The unconditional stability of the general fi... In this paper we are going to discuss the difference schemes with intrinsic parallelism for the boundary value problem of the two dimensional semilinear parabolic systems. The unconditional stability of the general finite difference schemes with intrinsic parallelism is justified in the sense of the continuous dependence of the discrete vector solution of the difference schemes on the discrete data of the original problems in the discrete w2(2,1)norms. Then the uniqueness of the discrete vector solution of this difference scheme follows as the consequence of the stability. 展开更多
关键词 difference scheme Intrinsic parallelism Two Dimensional Semilinear Parabolic System Stability.
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UNCONDITIONAL STABLE DIFFERENCE METHODS WITH INTRINSIC PARALLELISM FOR SEMILINEAR PARABOLIC SYSTEMS OF DIVERGENCE TYPE 被引量:4
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作者 ZHOUYULIN SHENLONGJUN YUANGUANGWEI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2004年第2期213-224,共12页
The general finite difference schemes with intrinsic parallelism for the boundary value problem of the semilinear parabolic system of divergence type with bounded measurable coefficients is studied. By the approach of... The general finite difference schemes with intrinsic parallelism for the boundary value problem of the semilinear parabolic system of divergence type with bounded measurable coefficients is studied. By the approach of the discrete functional analysis, the existence and uniqueness of the discrete vector solutions of the nonlinear difference system with intrinsic parallelism are proved. Moreover the unconditional stability of the general difference schemes with intrinsic parallelism justified in the sense of the continuous dependence of the discrete vector solution of the difference schemes on the discrete initial data of the original problems in the discrete W_2^(2,1) (Q△) norms. Finally the convergence of the discrete vector solutions of the certain difference schemes with intrinsic parallelism to the unique generalized solution of the original semilinear parabolic problem is proved. 展开更多
关键词 difference scheme Intrinsic parallelism Parabolic system STABILITY CONVERGENCE
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THE UNCONDITIONAL CONVERGENT DIFFERENCE METHODS WITH INTRINSIC PARALLELISM FOR QUASILINEAR PARABOLIC SYSTEMS WITH TWO DIMENSIONS 被引量:3
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作者 LongjunShen GuangweiYuan 《Journal of Computational Mathematics》 SCIE CSCD 2003年第1期41-52,共12页
In the present work we are going to solve the boundary value problem for the quasilinear parabolic systems of partial differential equations with two space dimensions by the finite difference method with intrinsic par... In the present work we are going to solve the boundary value problem for the quasilinear parabolic systems of partial differential equations with two space dimensions by the finite difference method with intrinsic parallelism. Some fundamental behaviors of general finite difference schemes with intrinsic parallelism for the mentioned problems are studied. By the method of a priori estimation of the discrete solutions of the nonlinear difference systems, and the interpolation formulas of the various norms of the discrete functions and the fixed-point technique in finite dimensional Euclidean space, the existence of the discrete vector solutions of the nonlinear difference system with intrinsic parallelism are proved. Moreover the convergence of the discrete vector solutions of these difference schemes to the unique generalized solution of the original quasilinear parabolic problem is proved. 展开更多
关键词 difference scheme Intrinsic parallelism Two Dimensional Quasilinear Parabolic System EXISTENCE Convergence.
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Finite Difference Analysis of Time-Dependent Viscous Nanofluid Flow Between Parallel Plates 被引量:1
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作者 Salman Ahmad T.Hayat +2 位作者 A.Alsaedi Z.H.Khan M.Waleed Ahmed Khan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2019年第11期1293-1300,共8页
This article computes effect of uniform magnetic field on nanofluid flow filling porous medium inside parallel sheets. Darcy's law is used to characterize porous medium. Flow is caused by stretching of the lower s... This article computes effect of uniform magnetic field on nanofluid flow filling porous medium inside parallel sheets. Darcy's law is used to characterize porous medium. Flow is caused by stretching of the lower sheet. The governing systems are computed using Finite difference technique. This scheme is used due to its more general and powerful nature to solve nonlinear problems. Results are obtained and discussed graphically. Nusselt number, skin friction, streamlines,velocity and temperature are emphasized. 展开更多
关键词 finite difference scheme porous medium magnetic field NANOFLUID parallel STRETCHABLE SHEETS
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Allen-Cahn方程的一种并行差分方法
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作者 梁琪琪 全赛君 +1 位作者 岳宏杰 韩丹夫 《杭州师范大学学报(自然科学版)》 CAS 2024年第6期659-667,共9页
文章给出了具有纽曼边界条件的Allen-Cahn方程的交替分段Crank-Nicolson格式.结合经典Crank-Nicolson格式和4种不同类型的Saul‘yev非对称格式构造了ASC-N并行差分格式,对ASC-N格式的唯一性进行了理论分析,并讨论了数值算法的离散最大... 文章给出了具有纽曼边界条件的Allen-Cahn方程的交替分段Crank-Nicolson格式.结合经典Crank-Nicolson格式和4种不同类型的Saul‘yev非对称格式构造了ASC-N并行差分格式,对ASC-N格式的唯一性进行了理论分析,并讨论了数值算法的离散最大值原理.理论分析与数值结果表明,在网格密度较大时,ASC-N并行格式相较于经典的Crank-Nicolson格式可大幅度节省计算时间,高效求解Allen-Cahn方程. 展开更多
关键词 Allen-Cahn方程 ASC-N方法 离散最大值原理 并行差分格式
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双曲型方程的有限差分并行迭代算法 被引量:3
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作者 金承日 丁效华 张少太 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2002年第3期340-343,共4页
为研究二阶双曲型偏微分方程适合于并行机上运行的高效率的计算方法 ,先构造出高精度无条件稳定的隐式差分格式 ,然后以此隐格式为基础 ,设计出适合于并行计算的完全显式的迭代算法 .数值结果表明 。
关键词 有限差分 双曲型方程 差分格式 并行迭代算法 收敛性 偏微分方程
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基于Boltzmann模型方程的气体运动论HPF并行算法 被引量:10
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作者 李志辉 张涵信 符松 《计算物理》 CSCD 北大核心 2003年第1期1-8,共8页
 从修正的BGK Boltzmann模型方程出发,引入离散速度坐标技术对气体分子速度分量进行离散降维,基于非定常时间分裂数值计算方法和无波动、无自由参数的NND耗散差分格式,发展直接求解气体分子速度分布函数的气体运动论有限差分数值格式,...  从修正的BGK Boltzmann模型方程出发,引入离散速度坐标技术对气体分子速度分量进行离散降维,基于非定常时间分裂数值计算方法和无波动、无自由参数的NND耗散差分格式,发展直接求解气体分子速度分布函数的气体运动论有限差分数值格式,提出一套能有效模拟各流域三维绕流问题的气体运动论统一算法.在分析研究气体运动论数值算法内在并行度的基础上,开展各流域三维绕流问题统一算法的HPF(高性能FOR TRAN)并行化程序设计,建立一套能有效模拟各流域复杂外形体绕流的HPF并行算法软件.并进行了不同Knudsen(克努森)数下三维球体绕流及类"神舟号"返回舱外形体绕流的初步数值实验,将计算结果与过渡区有关实验数据及各流域气体绕流现象进行比较分析,证实了发展的气体运动论HPF并行算法在求解稀薄流到连续流不同流域复杂绕流问题方面的可行性. 展开更多
关键词 气体运动论 BOLTZMANN模型方程 离散速度坐标法 NND差分格式 HPF并行计算 空气动力学 计算流体力学
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稀薄流到连续流的气体运动论统一算法研究 被引量:21
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作者 李志辉 张涵信 《空气动力学学报》 CSCD 北大核心 2003年第3期255-266,共12页
通过引入碰撞松弛参数和当地平衡态分布函数对BGK模型方程进行修正,确定含流态控制参数的各流域均适用的气体分子速度分布函数简化控制方程。发展和应用离散速度坐标法于气体分子速度空间,利用一套在物理空间和时间上连续而在速度空间... 通过引入碰撞松弛参数和当地平衡态分布函数对BGK模型方程进行修正,确定含流态控制参数的各流域均适用的气体分子速度分布函数简化控制方程。发展和应用离散速度坐标法于气体分子速度空间,利用一套在物理空间和时间上连续而在速度空间离散的分布函数来代替原分布函数对速度空间的连续依赖性。基于非定常时间分裂数值计算方法和无波动、无自由参数的NND耗散格式,建立直接求解气体分子速度分布函数的气体运动论有限差分数值方法。发展可用于速度空间宏观取矩的离散速度数值积分方法,获取物理空间各点的流动参数,由此发展一套能有效模拟各流域三维绕流问题的气体运动论统一算法。研究气体运动论数值算法所适合的并行方案,基于统一算法的HPF并行实现,建立一套能有效模拟不同流域复杂外形体绕流的HPF并行算法软件。通过对不同Knudsen数的一维、二维、三维气体绕流问题进行数值计算表明,计算结果与有关实验数据及其它途径得到的研究结果吻合较好,证实了本文发展的统一算法在求解稀薄流到连续流不同流域复杂绕流问题方面的可行性。 展开更多
关键词 稀薄流 连续流 气体运动论 算法 HPF并行算法软件 离散速度坐标法 空气动力学
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抛物型方程移动界面的并行差分格式 被引量:2
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作者 袁光伟 杭旭登 《工程数学学报》 CSCD 北大核心 2004年第F12期121-126,共6页
本文构造了抛物型方程的带移动界面的一般并行差分格式,并证明了其稳定性。许多简单实用的差分格式都能从中导出。理论分析和数值试验检验了算法的稳定性,精度和并行性。
关键词 抛物型方程 差分格式 证明 并行性 界面 数值试验 稳定性 移动 算法 精度
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粒子输运离散纵标方程基于界面修正的并行计算方法 被引量:6
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作者 袁光伟 杭旭登 《计算物理》 CSCD 北大核心 2006年第6期637-641,共5页
为了改造粒子输运方程求解的隐式格式,研究设计适应大型并行计算机的并行计算方法,介绍一类求解粒子输运方程离散纵标方程组的基于界面修正的源迭代并行计算方法.应用空间区域分解,在子区域内界面处首先采用迎风显式差分格式进行预估,... 为了改造粒子输运方程求解的隐式格式,研究设计适应大型并行计算机的并行计算方法,介绍一类求解粒子输运方程离散纵标方程组的基于界面修正的源迭代并行计算方法.应用空间区域分解,在子区域内界面处首先采用迎风显式差分格式进行预估,构造子区域的入射边界条件,然后,在各个子区域内部进行源迭代求解隐式离散纵标方程组.在源迭代过程中,在内界面入射边界处采用隐式格式进行界面修正.数值算例表明该并行计算方法在精度、并行度、简单性诸方面均具有良好的性质. 展开更多
关键词 粒子输运方程 并行差分方法 迭代法 界面修正
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