基于CFD的固液两相流流型分析及阻力损失模型的研究

发布时间：2018-02-12 01:33

本文关键词： 管道输送固液两相流阻力损失计算流体力学原理数值模拟　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国矿产资源丰富,但大多位于偏僻的山区,新建铁路、公路等运输干线投资较大、建设时间长且对环境造成严重破坏。管道输送因成本低、效率高、占地少且污染小,越来越受到人们的重视。在运用管道对矿浆进行输送时,管道的阻力特性是管道输送技术中的关键问题之一,直接影响着整个管道系统输送压力大小、泵型、泵站数量以及管道材质及管壁厚度的选择,在整个管道输送系统中起着举足轻重的作用。因此,对阻力损失的研究具有十分重要的意义。此外,由于输送管线在铺设过程中受到地理位置的限制,高低起伏落差大,不再是水平铺设而是呈现坡度不等的倾斜铺设,因此,对复杂形态管道输送特性的研究尤为重要。由于固液两相流复杂的流动规律,进行纯粹的理论研究相当困难的,历来的研究往往主要基于试验,不仅耗费大量的人力、物力和时间且得到的均是经验公式,受实验条件的限制。基于此本文从固液两相流理论出发,结合计算流体力学原理,利用计算机对管道输送进行数值模拟与分析,论文的主要研究工作如下:(1)针对固体物料进行了相关的物理特性和浆体特性基础实验的研究,对固体物料及浆体内部运动机理进行了初探,为后续数值模拟实验参数的设置奠定基础。(2)基于计算流体力学(Computation Fluid Dynamics)采用多相流模型-欧拉模型并通过Fluent软件进行数值模拟,探讨了不同流速、颗粒浓度、颗粒粒径、颗粒密度、管道管径及倾角下管道出口处的浆体流速分布及固体颗粒浓度分布的变化规律,并分析了不同工况下阻力损失的变化规律,为实际工程提供良好的工程实践参考价值。(3)通过分析不同工况下的固体颗粒流动规律,得到管道输送阻力损失的主要来源,并通过分析仿真结果,拟合各输送因素与阻力损失的关系表达式,基于能量理论,依据量纲分析分别建立了水平和倾斜管道的阻力损失计算模型,并通过实测数据对模型进行验证,均达到很好的效果,为固液两相流管道输送阻力损失预测方面提供一定的借鉴价值。本文采用理论与实验相结合的方式,基于能量理论,结合计算流体力学原理对管道输送进行数值模拟与分析,不仅方便快捷,且能很好的观测管道内部的流型变化规律,对实际工程具有一定的实践指导意义。
[Abstract]:Our country is rich in mineral resources, but most of them are located in remote mountainous areas. The main transportation lines such as new railways and highways have a large investment, long construction time and serious damage to the environment. Due to low cost, high efficiency, less land occupation and less pollution, pipeline transportation has the advantages of low cost, high efficiency, small area and little pollution. The resistance characteristic of pipeline is one of the key problems in pipeline transportation technology, which directly affects the pressure and pump type of the whole pipeline system. The number of pumping stations, the selection of pipe material and the thickness of pipe wall play an important role in the whole pipeline transportation system. Therefore, the study of resistance loss is of great significance. Because the transportation pipeline is restricted by the geographical position in the course of laying, the height and height fluctuate greatly, it is not horizontal laying but inclined laying with different slope, so, It is very important to study the transportation characteristics of pipeline with complex shape. Because of the complex flow law of solid-liquid two-phase flow, it is very difficult to carry out pure theoretical research. The material resources and time are all empirical formulas, which are limited by experimental conditions. Based on this, based on the theory of solid-liquid two-phase flow and the principle of computational fluid dynamics, the numerical simulation and analysis of pipeline transportation are carried out by computer. The main research work of this paper is as follows: (1) the basic experiments on physical properties and slurry properties of solid materials have been carried out, and the motion mechanism of solid materials and slurry has been studied. In order to lay a foundation for the setting of experimental parameters for subsequent numerical simulation, the multiphase flow model-Euler model is adopted based on computational fluid dynamics (CFD) and the numerical simulation is carried out by Fluent software. The different velocity of flow, particle concentration and particle size are discussed. The variation law of particle density, slurry velocity distribution and solid particle concentration distribution at the outlet of pipeline under pipe diameter and dip angle are analyzed, and the variation law of resistance loss under different working conditions is analyzed. By analyzing the flow law of solid particles under different working conditions, the main source of pipeline transportation resistance loss is obtained, and the simulation results are analyzed. According to the energy theory and dimensional analysis, the calculation models of the resistance loss of horizontal and inclined pipelines are established, and the model is verified by the measured data. It can provide some reference value for predicting the resistance loss of solid-liquid two-phase pipeline transportation. In this paper, the method of combining theory with experiment, based on energy theory, is adopted. The numerical simulation and analysis of pipeline transportation based on the principle of computational fluid dynamics are not only convenient and quick, but also can well observe the variation of flow pattern in pipeline, and have a certain practical significance for practical engineering.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD50

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