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981.
两同心球间旋转流动类Lorenz方程组的静态分歧 总被引:3,自引:0,他引:3
对同心球间旋转流动的N av ier-S tokes方程谱展开后进行三模态截断,讨论了所得到的类Lorenz型方程组的分歧问题.给出了静态奇异点的条件,并计算出解分支.首先,简要介绍了Lorenz方程组以及用Lorenz截断法讨论非线性问题的意义,其次,推导同心球间旋转流动N av ier-S tokes方程的流函数-涡度形式,最后,讨论同心球间旋转流动的类Lorenz型方程组的分歧问题. 相似文献
982.
The stationary and nonstationary rotating Navier-Stokes equations with mixed boundary conditions are investigated in this paper. The existence and uniqueness of the solutions are obtained by the Galerkin approximation method. Next, θ-scheme of operator splitting algorithm is applied to rotating Navier-Stokes equations and two subproblems are derived. Finally, the computational algorithms for these subproblems are provided. 相似文献
983.
Jian-Wen Peng 《Journal of Global Optimization》2008,42(4):559-575
In this paper, we introduce a new system of generalized mixed quasi-variational-like inclusions with (A, η, m)-accretive operators and relaxed cocoercive mappings. By using the fixed point theorem of Nadler, we prove the existence
of solutions for this general system of generalized mixed quasi-variational-like inclusions and its special cases. The results
in this paper unify, extend and improve some known results in the literature. The novel proof method is simpler than those
iterative algorithm approach for proving the existence of solutions of all classes of system of set-valued variational inclusions
in the literature. 相似文献
984.
近来,Lutwak,Yang和Zhang提出了新几何体Γ_(-p)K的概念,获得一些结论.本文引入混合新几何体Γ_(-p,i)K的概念,即新几何体是它的特殊类,得到了混合新几何体的一些性质,并建立了相关的不等式. 相似文献
985.
In this paper, we develop a deterministic inventory model for deteriorating items with two warehouses by minimizing the net present value of the total cost. Deterioration rates of items in the two warehouses may be different. In addition, we allow for shortages and complete backlogging. We then prove that the optimal replenishment policy not only exists but also is unique under some condition. Further, the result reveals that the reorder interval based on the average total cost, if it exists, must be longer than that derived using net present value. Finally, we use Yang’s [H.L. Yang, European Journal of Operational Research 157 (2004) 344–356] numerical example to illustrate the model and conclude the paper with suggestions for possible future research. 相似文献
986.
Jeffrey D. Streets 《Journal of Geometric Analysis》2008,18(1):249-271
We study the gradient flow of the Riemannian functional ℱ(g):=∫
M
|Rm|2. This flow corresponds to a fourth-order degenerate parabolic equation for a Riemannian metric. We prove that the degeneracies
may be accounted for entirely by diffeomorphism flow, and hence we show short-time existence using the DeTurck method. We
prove L
2 derivative estimates of Bernstein-Bando-Shi type and use these to give a basic obstruction to long time existence and prove
a compactness theorem.
相似文献
987.
Experimental study on turbulent features in the negative transport region of asymmetric plane channel flow 总被引:1,自引:0,他引:1
Turbulent features of streamwise and vertical components of velocity in the negative transport region of asymmetric plane
channel flow have been studied experimentally in details. Experiments show that turbulent fluctuations in negative transport
region are suppressed, and their probability distributions are far from Gaussian. Besides, the skewness factors attain their
negative maxima at the position of the maximum mean velocity, whereas the flatness factors attain their positive maxima at
the same position.
The project supported by the National Natural Science Foundation of China (19872043) 相似文献
988.
989.
Vincent Guinot 《国际流体数值方法杂志》2001,37(3):341-359
Godunov‐type algorithms are very attractive for the numerical solution of discontinuous flows. The reconstruction of the profile inside the cells is crucial to scheme performance. The non‐linear generalization of the discontinuous profile method (DPM) presented here for the modelling of two‐phase flow in pipes uses a discontinuous reconstruction in order to capture shocks more efficiently than schemes using continuous functions. The reconstructed profile is used to define the Riemann problem at cell interfaces by averaging of the components of the variable in the base of eigenvectors over their domain of dependence. Intercell fluxes are computed by solving the Riemann problem with an approximate‐state solver. The adapted treatment of boundary conditions is essential to ensure the quality of the computational results and a specific procedure using virtual cells at both extremities of the computational domain is required. Internal boundary conditions can be treated in the same way as external ones. Application of the DPM to test cases is shown to improve the quality of computational results significantly. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
990.
Corneliu Balan 《Continuum Mechanics and Thermodynamics》2001,13(6):399-414
Received March 25, 2001 / Published online November 15, 2001 相似文献