Velocity Correction Coefficients in Pressure Correction–Type Model

Abstract

Velocity correction methods are often used in numerical models simulating fluid flows. This paper presents a new method to evaluate the velocity correction coefficient: an equation constructed from the coefficient matrix of the linearized momentum equations is simultaneously solved for the velocity correction coefficient. In addition, the implicit equation of correction coefficients (ECC) method includes a smoothing mechanism, which makes it numerically more stable than the commonly used Semi-Implicit Method for Pressure-Linked Equations-Consistent (SIMPLEC) method because larger relaxation factors and time steps can be used. The ECC method was integrated into a two-dimensional (2D) depth-integrated unstructured finite-volume method (FVM) model based on a hybrid mesh system (triangle and quadrilateral). It was demonstrated using one experimental case and a field case. According to the numerical tests, the proposed ECC method can not only enhance the numerical stability but also improve the computing efficiency due to the capability of using large relaxation factors and large time steps for the pressure correction–type models.