Finite difference method

About: Finite difference method is a research topic. Over the lifetime, 21603 publications have been published within this topic receiving 468852 citations. The topic is also known as: Finite-difference methods & FDM.

Design of a new dynamical core for global atmospheric models based on some efficient numerical methods

Abstract: A careful study on the integral properties of the primitive hydrostatic balance equations for baroclinic atmosphere is carried out, and a new scheme to design the global adiabatic model of atmospheric dynamics is presented. This scheme includes a method of weighted equal-area mesh and a fully discrete finite difference method with quadratic and linear conservations for solving the primitive equation system. Using this scheme, we established a new dynamical core with adjustable high resolution acceptable to the available computer capability, which can be very stable without any filtering and smoothing. Especially, some important integral properties are kept unchanged, such as the anti-symmetries of the horizontal advection operators and the vertical convection operator, the mass conservation, the effective energy conservation under the standard stratification approximation, and so on. Some numerical tests on the new dynamical core, respectively regarding its global conservations and its integrated performances in climatic modeling, incorporated with the physical packages from the Community Atmospheric Model Version 2 (CAM2) of National Center for Atmospheric Research (NCAR), are included.

A full finite difference time domain implementation for radio wave propagation in a plasma

Abstract: A full finite difference time domain methodology is developed for electromagnetic wave propagation in a plasma The finite difference grid is consistent with central difference approximation of the curl, divergence and gradient operators that appear in the joint equations of Euler and Maxwell, and the coupling effects between the fluid velocity and the electric field To accomplish the time advancement, the central difference approximation is invoked for the time derivatives and leapfrog concepts are employed The resulting difference equations converge to the exact equations, provided that the developed stability requirement is satisfied Finally, numerical results are provided and compared with the inverse fast Fourier transform results of closed-form, frequency domain solutions for the half space problem; the agreement between solutions is shown to be excellent

Comparison of the Finite Volume and Lattice Boltzmann Methods for Solving Natural Convection Heat Transfer Problems inside Cavities and Enclosures

Abstract: Different numerical methods have been implemented to simulate internal natural convection heat transfer and also to identify the most accurate and efficient one. A laterally heated square enclosure, filled with air, was studied. A FORTRAN code based on the lattice Boltzmann method (LBM) was developed for this purpose. The finite difference method was applied to discretize the LBM equations. Furthermore, for comparison purpose, the commercially available CFD package FLUENT, which uses finite volume Method (FVM), was also used to simulate the same problem. Different discretization schemes, being the first order upwind, second order upwind, power law, and QUICK, were used with the finite volume solver where the SIMPLE and SIMPLEC algorithms linked the velocity-pressure terms. The results were also compared with existing experimental and numerical data. It was observed that the finite volume method requires less CPU usage time and yields more accurate results compared to the LBM. It has been noted that the 1st order upwind/SIMPLEC combination converges comparatively quickly with a very high accuracy especially at the boundaries. Interestingly, all variants of FVM discretization/pressure-velocity linking methods lead to almost the same number of iterations to converge but higher-order schemes ask for longer iterations.