Numerical Simulation Of 3-D Free Surface Turbulent Flow And The Use In Waterpower Project

Three dimension and turbulent are common characteristic of fluid flow problem in nature and added free surface for the best familiar fluid-water, such as flood discharge flow around frusta of brake in waterpower project, flow around hull in ship engineering, and so on, all have the three characteristics which are the very important study content and aspects in CFD.A comprehensive review and expectation about researching status in quo and development trends of viscous flow numerical simulation technique are given in this paper and grids generation methods, numerical computation methods, turbulent model and moving boundary simulation methods are the emphasis study in the paper. On the basic of above job a mathematical model of simulation turbulent flow with free surface is established and triumphantly applied to numerical computation on 2D spillway and 3D spillway with frusta of brake.The material job and main conclusion are as follows:(1)A simple boundary orthogonalization procedure independence grids generation method is put forward on the base of algebraic grid generation method; Data structure and computational model on interface are established aiming at blocks of structured grids.(2) SIMPLE procedure is established in nonorthogonal grids by use of the finite volume method and in-depth discusses on special topic such as boundary condition in nonorthogonal grids, deferred correction method and grads compute on calculational nodes, and so on. The SIMPLE procedure in nonorthogonal grids established in the paper is proved to be reasonable through representative numerical simulation such as incline square cavity driving flow, flow around back sidestep, flow around cylinder.(3) Characteristic and application range of different turbulent model are studied and compared and compute compare RNGk-ε turbulent model with k-ε model is established by the case of viscous flow through hydrofoil and the result show that better characteristic turbulent flow can be obtained by RNGk-ε.(4) VOF method in moving boundary simulation method is studied and ahigher precision free surface reconstruction model is established detailedly. The method is proved to well and truly confirm the shape and location of motion interface through numerical simulation of representative motion interface.(5) Compute of flow over 2D spillway is done by use of established free surface turbulent mathematical model in nonorthogonal grids and location of free surface, pressure on dam and flow characteristic on the such as flux, velocity of flow of different water height of dam peak are analyzed and the result of height of free surface and negative extremum of pressure on dam surface are well inosculate to result of representative experiment.(6) 3D integer model of spillway and frusta of brake are established and numerical computation of 3D viscous flow over spillway is completed. The influence of frusta of brake for design parameters such as shape of free surface,pressure on dam,flux coefficient is computed aim at type of frusta of brake and disposal on dam and compute result of different type of frusta and disposal model is compared. The result show that the position of free surface is higher because of frusta of brake, especial obvious in the head of frusta of brake; flux coefficient and pressure on dam are quite influenced by type of frusta and 3 A type frusta of brake relative to 2 type frusta of brake has bigger flux coefficient and smaller pressure on dam; Obvious influence of ability of discharge flow for different ratio of thickness of frusta and breadth of brake and pressure on dam reduces with increasing ration of thickness of frusta and breadth of brake, while bigger flux coefficient is obtained when tlb = 0.2.(7)The 3D free surface turbulent model established in the paper is comparatively well and truly simulates 3D flow over spillway with frusta of brake and series waterpower computation can be completed aim at different type of dam, type of frusta and disposal on the dam and different water height on peak of...