【作者】 王毅；

【导师】 曾良才；

【作者基本信息】 武汉科技大学 ， 机械电子工程， 2008， 硕士

【摘要】 在热轧带钢生产过程中,除鳞一直是不可缺少的一道重要工序,目前国内外多采用高压水除鳞技术,而在高压水除鳞系统中,喷嘴既是射流发生元件也是系统中的关键部件,其功能不仅是把高压泵组提供的静压转换为水的动能,而且要保证射流具有良好的流动特性和动力性能。因此研究和优化喷嘴的几何结构,建立喷嘴结构参数与其射流特性之间的关系,对提高系统除鳞效果有重要意义。本文运用数值模拟的仿真分析与实验研究对照的方法,首先应用CFD软件Fluent对高压除鳞喷嘴的内外流场进行了三维数值模拟和仿真分析,然后在自行研发的喷嘴实验台上对与仿真模型中同规格的喷嘴进行实验,通过理论与实际相结合,研究了高压除鳞喷嘴各结构参数和各种工况对其内外流场和喷射打击力的影响关系,具体研究内容如下:(1)应用前处理软件Gambit建立了喷嘴内部流场的三维模型,采用Fluent软件提供的Laminar层流模型对不同结构参数的喷嘴内部不可压缩、稳态、层流流场进行了数值模拟。分析了喷嘴收缩角、扩张角和直径等参数对其流场速度分布、压力分布和出口轴心速度的影响。(2)通过对高压水除鳞喷嘴外部气液两相亚声速湍流流场进行了三维建模仿真,研究水流离开喷嘴进入到空气中的压力分布和速度分布规律,并通过变参数仿真探讨系统压力和靶距对其喷射流场和打击力分布范围的影响,从而预测出最佳靶距,为确定喷嘴水平间距和工作高度提供了有力的理论依据。(3)利用武汉科技大学流体传动与控制研究所研制的高压除鳞喷嘴性能测试实验台及自行开发的相关测试软件,通过对所选型号喷嘴的射流特性进行实验,得到系统压力、靶距、射流打击力、射流宽度等参数之间的相互关系,并与之前的理论计算和仿真结果进行对比,验证数值仿真的正确性,从而指导喷嘴的加工、选型和布局。更多还原

【Abstract】 In the hot strip production process,descaling has been an indispensable important processes, the current technology that domestic and international use is high-pressure water descaling, and in the high-pressure water descaling system, the jet nozzle is the key components, its function is not only to convert the water pressure which provide by high-pressure pumps to kinetic energy, but also to ensure that Jet has a good flow characteristics and dynamic performance. So the study and optimization of the nozzle geometry,establish the relationship between the structural parameters of jet nozzle and its jet property have important meaning to increase the effects of descaling system.This paper uses numerical simulation of simulation analysis and experimental research.First apply CFD software FLUENT to simulate the three-dimensional flow field and analyse simulation result of the inside and outside flow field of the Descaling high-pressure nozzle, and then developed a nozzle experimental stage,experiment on the nozzle which has the same specifications with the simulation model,combine the theoretical and practical,study the relationgships between the construct parameters of the nozzle,the various status and the internal and external flow field and jet combat, the specific research content is as follows:(1)A three-dimensional mathematical model of internal flow field in high-pressure descaling nozzle was established by the Gambit software.Using the Laminar model offered by Fluent software to simulate the incompressible,steady state internal flow field of the nozzles with different constructional parameters,and analysed the influence of nozzle parameters which include the astringent angle,the diffuse angle and diameter on the velocity distribution,pressure distribution and outlet axial velocity of the flow field.(2)Through the three-dimensional modeling and simulation to the subsonic gas-liquid two-phase turbulent external flow field of high-pressure water descaling nozzle.study the pressure distribution and velocity distribution after water spray into the air from the nozzle.discuss the the impact that system pressure and the target distance to the Jet flow and the scope distribution of combat force by simulation of the variable parameters.then forecast the best target distance,provide a strong theoretical basis to determine the level spacing and height of the nozzle.(3)Using the High-pressure Descaling nozzle performance experiment table and the related software which developed by fluid transmission and control Institute of Wuhan University of Science and Technology, through testing the jet characteristics of the nozzle which model has been selected.find the relationship of parameters such as system pressure, target distance, jet attack force and jet width.compare with the theoretical calculations and simulation results which we obtain before, validate the accuracy of numerical simulation, thereby guiding processing, selection and layout of the nozzle.更多还原