Numerical accuracy, numerical stability and calculation time are all important factors in the computational fluid dynamics. In this study, we compare two solution algorithms, the Simplified Marker and Cell (SMAC) method in the MAC-type methods and the Semi-Implicit Method for Pressure-Linked Equation (SIMPLE) algorithm in the SIMPLE-type algorithms, with respect to flow around a square cylinder...

This paper investigates an artificial neural network (ANN) model for typhoon waves used to modify poor calculations of the numerical model in special cases. Two key factors, local winds and simulated waves produced by the numerical model, were used as input parameters of the proposed ANNmodel. The waves were simulated by the numerical model from a wave action equation indicating the physical pr...

DV-Xα method uses natural and high grade numerical AOs, which generate very precise MOs for a wide variety of molecules within the restriction of LCAO approximation. But Monte-Carlo integration used here causes serious numerical errors for total energy and energy gradient calculation. The author improved their calculation procedure, where the numerical error in physical quantity of a molecule i...

The pointwise error of a nite-di erence calculation of supersonic ow is discussed. The local truncation error is determined by a Taylor series with the remainder being in a Lagrange form. The contribution of the local truncation error to the total pointwise approximation error is estimated via adjoint parameters. It is demonstrated by numerical tests that the results of the numerical calculatio...

The numerical calculation of the Rayleigh-Sommerfeld diffraction integral is investigated. The implementation of a fast-Fourier-transform (FFT) based direct integration (FFT-DI) method is presented, and Simpson's rule is used to improve the calculation accuracy. The sampling interval, the size of the computation window, and their influence on numerical accuracy and on computational complexity a...

Abstract Application of numerical models is useful in coastal sediment studies; however, it is essential to calibrate the models in an appropriate method. Empirical equations, historical satellite imagery and other coastal data and evidence are proposed for the models calibration in the vicinity of coastal indicators around the site of projects. In this study, coastal sediment process of K...

A numerical investigation of entropy generation in laminar forced convection of gas flow over a backward facing step in a horizontal duct under bleeding condition is presented. For calculation of entropy generation from the second law of thermodynamics in a forced convection flow, the velocity and temperature distributions are primary needed. For this purpose, the three-dimensional Cartesian co...

In this paper, the problems of calculating and solution about electromagnetic fields were studied. An accurate theory model was established which can apply in high-performance numerical calculation. The new calculating method was proposed using Maxwell’s equations in the circumstances of that electromagnetic field is static, axial symmetric, without charge and current distribution, finite, diff...

It is generally agreed that of all quadrature formulae, the trapezoidal rule, while being the simplest, is also the least accurate. There is, however, a rather general class of integrals for which the trapezoidal rule can be shown to be a highly accurate means of obtaining numerical values. Specifically, if the integrand is a periodic, even function with all derivatives continuous, then the int...