排序方式： 共有3条查询结果，搜索用时 0 毫秒
1
1.
A complication of finite-volume triangular C-grid methods is the numerical emergence of horizontal divergence errors that lead to grid-scale oscillations in vertical velocity. Nonlinear feedback via advection of momentum can lead to numerical instability in velocity modes via positive feedback with spurious vertical velocities induced by horizontal divergence truncation error. Existing strategies to mitigate divergence errors such as direct divergence averaging and increased diffusion do not completely mitigate horizontal vertical velocity oscillations. We present a novel elliptic filtering approach to mitigate this spurious error and more accurately represent vertical velocities via improved calculation of horizontal divergences. These results are applied to laminar curved channel flows, demonstrating the applicability of the method to reproduce secondary flow features. 相似文献
2.
The baroclinic primitive equation model used for short and medium range forecasting admits high frequency as well as desirable
Rossby modes. These high frequency oscillations are excited by initial imbalances between the observed mass and wind fields.
In this paper we determine and describe the normal modes of the linearized version of the general circulation model of Laboratoire
de Meteorologie Dynamique, Paris. These normal modes are then used to initialize the model through Machenhauer’s nonlinear
correction scheme. The adiabatic nonlinear normal mode initialization technique is shown to be superior to dynamic initialization
in terms of elimination of high-frequency oscillations in the forecast. Normal modes of a particular model depend on the finite
difference scheme chosen to approximate the governing system of model equations. The results presented correspond to enstrophy-conserving
finite difference scheme. 相似文献
3.
A two-dimensional coastal ocean model based on unstructured C-grid is built, in which the momentum equation is discretized on the faces of each cell, and the continuity equation is discretized on the cell. The model is discretized by semi-implicit finite volume method, in that the free surface is semi-implicit and the bottom friction is implicit, thereby removing stability limitations associated with the surface gravity wave and friction. The remaining terms in the momentum equations are discretized explicitly by integral finite volume method and second-order Adams-Bashforth method. Tidal flow in the polar quadrant with known analytic solution is employed to test the proposed model. Finally, the performance of the present model to simulate tidal flow in a geometrically complex domain is examined by simulation of tidal currents in the Pearl River Estuary. 相似文献
1