Two-Dimensional Mathematical Model Of The Flows And Sedimentation And Its Application To Natural River Natural River

The computational ?uid dynamics is the combination of modern ?uid dynam-ics,numerical mathematics and computer science, and is strong vitality borderline science.With the rapid development of various CFD technology,it provides universal extension andapplication in many industries. Two-dimensional mathematical model is an important meanof water and sand simulated in natural environment or after building and regulating engineer-ing. The SIMPLE algorithm as a typical finite volume method is used to find the solution.Numerical simulation of water and sediment for Ningxia shapotou is conduct, which the so-lution agrees well with the measured data and movement rules of water and sediment. Thefollowing are the main works:(1) Governing Equations are discreted by the volume method. Discrete format of convec-tion item and the treatment of outlet boundary are stated. The TDMA algorithm is introducedin detail, because the discrete equation is five diagonal.(2) SIMPLE algorithm is introduced and improved–adaptive method of stress relaxationfactor. Compared with the tradition method that is setting value stress relaxation factor,thealgorithm can get the convergent solution without guessing the pressure relaxation factor.(3) A interpolation method is structured to generate center point based on the feature ofriver course and Hermite interpolation, then both sides points are generated. The methodimproves the quality of grid generation, and are conducive to numerical simulation of waterand sediment. After mesh generation, numerical simulation of water is conducted. The ?owrate and water level of some sections agree well with the measured vale.(4) Numerical simulation of water and sediment of Ningxia shapotou yellow river is con-ducted based on numerical simulation of water. The simulation accords with water andsediment migration rule. Accurate numerical simulation contributes to hold rivers trendsof Yellow River and management provide of the middle and lower reaches of managementprovide of Yellow River.